Bluetooth status indicator

Introduce the new Bluetooth indicator in the System Status area. It
is written in JS with St and uses the new GnomeBluetoothApplet library.

https://bugzilla.gnome.org/show_bug.cgi?id=618312

js/ui/main.js

@@ -135,6 +135,7 @@ function start() {
     notificationDaemon = new NotificationDaemon.NotificationDaemon();
     windowAttentionHandler = new WindowAttentionHandler.WindowAttentionHandler();
     telepathyClient = new TelepathyClient.Client();
+    panel.startStatusArea();
 
     _startDate = new Date();