Renamed MessageListActivity to MainActivity

(it is the main activity, after all)

app/src/main/java/ch/dissem/apps/abit/MessageDetailActivity.java

@@ -3,7 +3,6 @@ package ch.dissem.apps.abit;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.v4.app.NavUtils;
-import android.support.v7.app.ActionBarActivity;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.view.MenuItem;
@@ -13,7 +12,7 @@ import android.view.MenuItem;
  * An activity representing a single Message detail screen. This
  * activity is only used on handset devices. On tablet-size devices,
  * item details are presented side-by-side with a list of items
- * in a {@link MessageListActivity}.
+ * in a {@link MainActivity}.
  * <p/>
  * This activity is mostly just a 'shell' activity containing nothing
  * more than a {@link MessageDetailFragment}.
@@ -64,7 +63,7 @@ public class MessageDetailActivity extends AppCompatActivity {
             //
             // http://developer.android.com/design/patterns/navigation.html#up-vs-back
             //
-            NavUtils.navigateUpTo(this, new Intent(this, MessageListActivity.class));
+            NavUtils.navigateUpTo(this, new Intent(this, MainActivity.class));
             return true;
         }
         return super.onOptionsItemSelected(item);