lint warnings fixed

android-app-core/res/values/preferences.xml

@@ -1,27 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-  ~ Copyright 2013 serso aka se.solovyev
-  ~
-  ~ Licensed under the Apache License, Version 2.0 (the "License");
-  ~ you may not use this file except in compliance with the License.
-  ~ You may obtain a copy of the License at
-  ~
-  ~    http://www.apache.org/licenses/LICENSE-2.0
-  ~
-  ~ Unless required by applicable law or agreed to in writing, software
-  ~ distributed under the License is distributed on an "AS IS" BASIS,
-  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  ~ See the License for the specific language governing permissions and
-  ~ limitations under the License.
-  ~
-  ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-  ~ Contact details
-  ~
-  ~ Email: se.solovyev@gmail.com
-  ~ Site:  http://se.solovyev.org
-  -->
-
-<resources>
-	<string name="p_calc_functions">org.solovyev.android.calculator.CalculatorModel_functions</string>
-	<string name="p_calc_vars">org.solovyev.android.calculator.CalculatorModel_vars</string>
-</resources>