Add "Show queue" to Action list

User can now select "Show queue" as an action when interacting (press,
long press, swipe up, swipe down) with the Cover in the Playback Screen.

res/values/untranslatable.xml

@@ -52,6 +52,7 @@ THE SOFTWARE.
 		<item>EnqueueArtist</item>
 		<item>EnqueueGenre</item>
 		<item>ClearQueue</item>
+		<item>ShowQueue</item>
 		<item>ToggleControls</item>
 	</string-array>
 	<string-array name="swipe_action_entries">
@@ -69,6 +70,7 @@ THE SOFTWARE.
 		<item>@string/enqueue_current_artist</item>
 		<item>@string/enqueue_current_genre</item>
 		<item>@string/clear_queue</item>
+		<item>@string/show_queue</item>
 		<item>@string/toggle_controls</item>
 	</string-array>
 	<string-array name="default_playlist_action_entries">

src/ch/blinkenlights/android/vanilla/Action.java

@@ -80,6 +80,10 @@ enum Action {
 	 * Clear the queue of all remaining songs.
 	 */
 	ClearQueue,
+	/**
+	 * Show the queue.
+	 */
+	ShowQueue,
 	/**
 	 * Toggle the controls in the playback activity.
 	 */

src/ch/blinkenlights/android/vanilla/PlaybackService.java

@@ -1912,6 +1912,11 @@ public final class PlaybackService extends Service
 			clearQueue();
 			Toast.makeText(this, R.string.queue_cleared, Toast.LENGTH_SHORT).show();
 			break;
+		case ShowQueue:
+			Intent intentShowQueue = new Intent(this, ShowQueueActivity.class);
+			intentShowQueue.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
+			startActivity(intentShowQueue);
+			break;
 		case ToggleControls:
 			// Handled in FullPlaybackActivity.performAction
 			break;