Improve the GDK API for dealing with group leaders (#119375):

Improve the GDK API for dealing with group leaders (#119375):

Wed Dec 10 00:06:24 2003  Matthias Clasen  <maclas@gmx.de>

	Improve the GDK API for dealing with group leaders (#119375):

	* gdk/gdkwindow.h:
	* gdk/x11/gdkwindow-x11.c (gdk_window_get_group): New function to
	get the group leader of a toplevel window as a GdkWindow.

	* gdk/gdkdisplay.h:
	* gdk/x11/gdkdisplay-x11.c (gdk_display_get_default_group): New
	function to get the default group leader as a GdkWindow.

	* gdk/x11/gdkdisplay-x11.h (struct _GdkDisplayX11): Add a field for
	the GdkWindow of the default group leader.

	* gdk/x11/gdkdisplay-x11.c (gdk_display_open): Construct the GdkWindow
	for the default group leader.