Project restructure

We don't need to separate widget/onscreen from the main module, let's merge them together.

android-app/src/main/res/layout/onscreen_layout.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
+			  a:orientation="vertical"
+			  style="@style/cpp_onscreen_main_layout_style">
+
+	<include
+			a:id="@+id/onscreen_header"
+			layout="@layout/onscreen_header"/>
+
+	<LinearLayout
+			a:id="@+id/onscreen_content"
+			a:orientation="vertical"
+			a:layout_width="match_parent"
+			a:layout_height="match_parent">
+
+		<include
+				layout="@layout/onscreen_editor"
+				a:layout_width="match_parent"
+				a:layout_height="wrap_content"/>
+
+		<LinearLayout
+				a:layout_weight="1"
+				a:layout_width="match_parent"
+				a:layout_height="0dp">
+
+			<include
+					layout="@layout/cpp_simple_button_equals"
+					a:layout_margin="@dimen/cpp_button_margin"
+					a:layout_weight="1"
+					a:layout_width="0dp"
+					a:layout_height="match_parent"/>
+
+			<include
+					layout="@layout/onscreen_display"
+					a:layout_weight="4"
+					a:layout_width="0dp"
+					a:layout_height="wrap_content"/>
+
+		</LinearLayout>
+
+		<include
+				layout="@layout/onscreen_keyboard"
+				a:layout_weight="4"
+				a:layout_width="match_parent"
+				a:layout_height="0dp"/>
+	</LinearLayout>
+
+	<include layout="@layout/onscreen_footer"/>
+
+</LinearLayout>