Add private backend data to events, and handle it when copying/freeing

Add private backend data to events, and handle it when copying/freeing

2008-05-06  Richard Hult  <richard@imendio.com>

	* gdk/gdkevents.c: (gdk_event_copy), (gdk_event_free):
	* gdk/gdkinternals.h: Add private backend data to events, and
	handle it when copying/freeing events. Currently only needed in
	the quartz backend.

	* gdk/directfb/gdkevents-directfb.c:
	* gdk/quartz/gdkevents-quartz.c:
	* gdk/win32/gdkevents-win32.c:
	* gdk/x11/gdkevents-x11.c: (_gdk_windowing_event_data_copy)
	(_gdk_windowing_event_data_free): Add stubs for X11, win32 and
	directfb. Implement for quartz. Part of fixing bug #473822.

svn path=/trunk/; revision=20078