Fixes / Improvements

- some fixes for tablets
- updated API
- removed BitmessageService (I really hope it won't be needed)

app/src/main/res/layout-sw600dp/activity_message_list.xml

@@ -1,4 +1,5 @@
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+                xmlns:app="http://schemas.android.com/apk/res-auto"
                 android:gravity="center"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent">
@@ -8,7 +9,9 @@
             android:layout_width="match_parent"
             android:layout_height="?attr/actionBarSize"
             android:background="?attr/colorPrimary"
-            android:elevation="4dp"/>
+            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
+            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
+            android:elevation="4dp" />
 
     <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                   xmlns:tools="http://schemas.android.com/tools"
@@ -34,6 +37,7 @@
                 android:layout_width="0dp"
                 android:layout_height="match_parent"
                 android:layout_weight="1"
+                tools:context=".MessageListActivity"
                 tools:layout="@android:layout/list_content"/>
 
         <FrameLayout