diff --git a/android-app-tests/android-app-tests.iml b/android-app-tests/android-app-tests.iml
index 16d6d5d4..ef5b97dd 100644
--- a/android-app-tests/android-app-tests.iml
+++ b/android-app-tests/android-app-tests.iml
@@ -32,8 +32,8 @@
     <orderEntry type="library" exported="" scope="TEST" name="robolectric-2.3" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="mockito-all-1.9.5" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="jsonassert-1.2.3" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="support-v4-21.0.3" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="appcompat-v7-21.0.3" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="support-v4-22.1.1" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="appcompat-v7-22.1.1" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="hamcrest-core-1.3" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="objenesis-1.3" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="sqlite4java-0.282" level="project" />
@@ -73,40 +73,42 @@
     <orderEntry type="library" exported="" scope="TEST" name="wagon-http-shared-1.0-beta-6" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="xercesMinimal-1.9.6.2" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="nekohtml-1.9.6.2" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="support-annotations-21.0.3" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="support-annotations-22.1.1" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="simple-xml-2.6.1" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="core" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_com_android_support_recyclerview_v7_21_0_0_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="support-annotations-22.1.1" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_com_android_support_support_v4_22_1_1_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_core_build_libs_core_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="commons-cli-1.2" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="annotations-2.0.1" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_com_google_android_gms_play_services_ads_6_5_87_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_com_melnykov_floatingactionbutton_1_1_0_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_android_common_menus_1_1_18_jars_classes_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="stax-1.2.0" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="support-annotations-21.0.3" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="leakcanary-watcher-1.3" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_com_squareup_leakcanary_leakcanary_android_1_3_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_android_common_other_1_1_18_jars_classes_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="common-msg-1.0.5" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="common-listeners-1.0.7" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_android_common_preferences_1_1_18_jars_classes_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="guava-11.0.2" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="common-text-1.0.7" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_checkout_0_7_2_jars_classes_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="library-2.4.0" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="common-text-1.0.7" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_material_0_1_2_jars_classes_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="acra-4.5.0" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="internal_impl-21.0.3" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
-    <orderEntry type="library" exported="" scope="TEST" name="classes" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_android_common_views_1_1_18_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_com_google_android_gms_play_services_base_6_5_87_jars_classes_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="common-core-1.0.7" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_android_common_core_1_1_18_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="haha-1.1" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="common-security-1.0.7" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="jscl-1.0.11" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="leakcanary-analyzer-1.3" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_org_solovyev_android_android_common_lists_1_1_18_jars_classes_jar" level="project" />
+    <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_exploded_aar_com_android_support_appcompat_v7_22_1_1_jars_classes_jar" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_classes_debug" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="_home_serso_projects_java_serso_android_calculatorpp_android_app_build_intermediates_dependency_cache_debug" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="android" level="project" />
-    <orderEntry type="library" exported="" name="android-app-tests.android-app-tests" level="project" />
   </component>
 </module>
\ No newline at end of file
diff --git a/android-app/android-app.iml b/android-app/android-app.iml
index 70eb22f9..c936564c 100644
--- a/android-app/android-app.iml
+++ b/android-app/android-app.iml
@@ -13,9 +13,9 @@
         <option name="ASSEMBLE_TASK_NAME" value="assembleDebug" />
         <option name="COMPILE_JAVA_TASK_NAME" value="compileDebugSources" />
         <option name="SOURCE_GEN_TASK_NAME" value="generateDebugSources" />
-        <option name="ASSEMBLE_TEST_TASK_NAME" value="assembleDebugTest" />
-        <option name="COMPILE_JAVA_TEST_TASK_NAME" value="compileDebugTestSources" />
-        <option name="TEST_SOURCE_GEN_TASK_NAME" value="generateDebugTestSources" />
+        <option name="ASSEMBLE_TEST_TASK_NAME" value="assembleDebugAndroidTest" />
+        <option name="COMPILE_JAVA_TEST_TASK_NAME" value="compileDebugAndroidTestSources" />
+        <option name="TEST_SOURCE_GEN_TASK_NAME" value="generateDebugAndroidTestSources" />
         <option name="ALLOW_USER_CONFIGURATION" value="false" />
         <option name="MANIFEST_FILE_RELATIVE_PATH" value="/src/main/AndroidManifest.xml" />
         <option name="RES_FOLDER_RELATIVE_PATH" value="/src/main/res" />
@@ -26,7 +26,7 @@
   </component>
   <component name="NewModuleRootManager" inherit-compiler-output="false">
     <output url="file://$MODULE_DIR$/build/intermediates/classes/debug" />
-    <output-test url="file://$MODULE_DIR$/build/intermediates/classes/test/debug" />
+    <output-test url="file://$MODULE_DIR$/build/intermediates/classes/androidTest/debug" />
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/r/debug" isTestSource="false" generated="true" />
@@ -35,12 +35,12 @@
       <sourceFolder url="file://$MODULE_DIR$/build/generated/source/rs/debug" isTestSource="false" generated="true" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/res/rs/debug" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/build/generated/res/generated/debug" type="java-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/r/test/debug" isTestSource="true" generated="true" />
-      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/aidl/test/debug" isTestSource="true" generated="true" />
-      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/buildConfig/test/debug" isTestSource="true" generated="true" />
-      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/rs/test/debug" isTestSource="true" generated="true" />
-      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/rs/test/debug" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/generated/test/debug" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/r/androidTest/debug" isTestSource="true" generated="true" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/aidl/androidTest/debug" isTestSource="true" generated="true" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/buildConfig/androidTest/debug" isTestSource="true" generated="true" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/source/rs/androidTest/debug" isTestSource="true" generated="true" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/rs/androidTest/debug" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/build/generated/res/generated/androidTest/debug" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/res" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/resources" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/assets" type="java-resource" />
@@ -69,6 +69,21 @@
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/dependency-cache" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/dex" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/dex-cache" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.android.support/appcompat-v7/22.1.1/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.android.support/recyclerview-v7/21.0.0/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.android.support/support-v4/22.1.1/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.google.android.gms/play-services-ads/6.5.87/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.google.android.gms/play-services-base/6.5.87/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.melnykov/floatingactionbutton/1.1.0/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/com.squareup.leakcanary/leakcanary-android/1.3/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/android-common-core/1.1.18/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/android-common-lists/1.1.18/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/android-common-menus/1.1.18/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/android-common-other/1.1.18/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/android-common-preferences/1.1.18/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/android-common-views/1.1.18/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/checkout/0.7.2/jars" />
+      <excludeFolder url="file://$MODULE_DIR$/build/intermediates/exploded-aar/org.solovyev.android/material/0.1.2/jars" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/incremental" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/jacoco" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/javaResources" />
@@ -81,41 +96,43 @@
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/res" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/rs" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/symbols" />
-      <excludeFolder url="file://$MODULE_DIR$/build/libs" />
       <excludeFolder url="file://$MODULE_DIR$/build/outputs" />
-      <excludeFolder url="file://$MODULE_DIR$/build/poms" />
       <excludeFolder url="file://$MODULE_DIR$/build/tmp" />
     </content>
-    <orderEntry type="jdk" jdkName="Android API 21 Platform" jdkType="Android SDK" />
+    <orderEntry type="jdk" jdkName="Android API 22 Platform" jdkType="Android SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" exported="" name="support-v4-21.0.3" level="project" />
+    <orderEntry type="library" exported="" name="leakcanary-watcher-1.3" level="project" />
     <orderEntry type="library" exported="" name="play-services-ads-6.5.87" level="project" />
     <orderEntry type="library" exported="" name="acra-4.5.0" level="project" />
     <orderEntry type="library" exported="" name="annotations-2.0.1" level="project" />
     <orderEntry type="library" exported="" name="common-core-1.0.7" level="project" />
     <orderEntry type="library" exported="" name="common-listeners-1.0.7" level="project" />
-    <orderEntry type="library" exported="" name="appcompat-v7-21.0.3" level="project" />
     <orderEntry type="library" exported="" name="common-text-1.0.7" level="project" />
     <orderEntry type="library" exported="" name="android-common-views-1.1.18" level="project" />
     <orderEntry type="library" exported="" name="stax-1.2.0" level="project" />
     <orderEntry type="library" exported="" name="jscl-1.0.11" level="project" />
     <orderEntry type="library" exported="" name="library-2.4.0" level="project" />
+    <orderEntry type="library" exported="" name="leakcanary-analyzer-1.3" level="project" />
     <orderEntry type="library" exported="" name="material-0.1.2" level="project" />
     <orderEntry type="library" exported="" name="android-common-menus-1.1.18" level="project" />
     <orderEntry type="library" exported="" name="recyclerview-v7-21.0.0" level="project" />
+    <orderEntry type="library" exported="" name="leakcanary-android-1.3" level="project" />
     <orderEntry type="library" exported="" name="common-security-1.0.7" level="project" />
     <orderEntry type="library" exported="" name="play-services-base-6.5.87" level="project" />
+    <orderEntry type="library" exported="" name="support-annotations-22.1.1" level="project" />
+    <orderEntry type="library" exported="" name="haha-1.1" level="project" />
     <orderEntry type="library" exported="" name="android-common-core-1.1.18" level="project" />
+    <orderEntry type="library" exported="" name="appcompat-v7-22.1.1" level="project" />
     <orderEntry type="library" exported="" name="common-msg-1.0.5" level="project" />
     <orderEntry type="library" exported="" name="android-common-other-1.1.18" level="project" />
     <orderEntry type="library" exported="" name="floatingactionbutton-1.1.0" level="project" />
-    <orderEntry type="library" exported="" name="android-common-preferences-1.1.18" level="project" />
     <orderEntry type="library" exported="" name="checkout-0.7.2" level="project" />
-    <orderEntry type="library" exported="" name="support-annotations-21.0.3" level="project" />
+    <orderEntry type="library" exported="" name="android-common-preferences-1.1.18" level="project" />
     <orderEntry type="library" exported="" name="android-common-lists-1.1.18" level="project" />
     <orderEntry type="library" exported="" name="guava-11.0.2" level="project" />
     <orderEntry type="library" exported="" name="commons-cli-1.2" level="project" />
     <orderEntry type="library" exported="" name="simple-xml-2.6.1" level="project" />
+    <orderEntry type="library" exported="" name="support-v4-22.1.1" level="project" />
     <orderEntry type="module" module-name="core" exported="" />
   </component>
 </module>
\ No newline at end of file
diff --git a/core/core.iml b/core/core.iml
index 9472019c..46989791 100644
--- a/core/core.iml
+++ b/core/core.iml
@@ -42,6 +42,5 @@
     <orderEntry type="library" exported="" scope="TEST" name="mockito-core-1.9.0" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="hamcrest-core-1.3" level="project" />
     <orderEntry type="library" exported="" scope="TEST" name="objenesis-1.0" level="project" />
-    <orderEntry type="library" exported="" name="core.core" level="project" />
   </component>
 </module>
\ No newline at end of file