* clutter/clutter-main.c:
(clutter_main): Destroy the main stage, instead of unreffing it.
(clutter_init): Ref and sink the main stage, as it is a top
level actor.
* clutter/clutter-stage.c (clutter_stage_unrealize): Access
the Window private member directly, instead of calling the
get_xwindow method.
* examples/test.c (main): Quit on button press.