Call g_main_context_wakeup() when we start running timelines

If a timeline is added from a different thread, we need to
call g_main_context_wakeup() to wake the main thread up to
start updating the timeline.

http://bugzilla.openedhand.com/show_bug.cgi?id=1637

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>

clutter/clutter-master-clock.c

@@ -264,6 +264,11 @@ _clutter_master_clock_add_timeline (ClutterMasterClock *master_clock,
     {
       /* Start timing from scratch */
       master_clock->prev_tick.tv_sec = 0;
+
+      /* If called from a different thread, we need to wake up the
+       * main loop to start running the timelines
+       */
+      g_main_context_wakeup (NULL);
     }
 }