This was pretty straightforward thanks to the work I did separating out
LibCore from LibGUI already. :^)
- WSMessageLoop now inherits from CEventLoop.
- WSMessage now inherits from CEvent.
- WSMessageReceiver goes away.
Now there is only one event loop in Serenity. Very nice!
The enabled state of a GAction now propagates both to any toolbar buttons
and any menu items linked to the action. Toolbar buttons are painted in
a grayed out style when disabled. Menu items are gray when disabled. :^)
