-Redone control panel in video detail fragment.

-Added playlist append menu item to channel and playlist fragments.
-Added debouncing to local playlist fragment to allow saving join when list is reordered or item is deleted.
-Extracted hardcoded strings.

app/src/main/res/layout/dialog_playlists.xml

@@ -28,7 +28,7 @@
             android:layout_height="50dp"
             android:layout_toRightOf="@+id/newPlaylistIcon"
             android:gravity="left|center"
-            android:text="Create New Playlist"
+            android:text="@string/create_playlist"
             android:textAppearance="?android:attr/textAppearanceLarge"
             android:textSize="15sp"
             android:textStyle="bold"