Add GdkEventSetting event for notification of changes to system settings,

Add GdkEventSetting event for notification of changes to system settings,

Mon Apr  2 18:18:07 2001  Owen Taylor  <otaylor@redhat.com>

        * gdk/gdkevents.h: Add GdkEventSetting event for notification
	of changes to system settings, gdk_setting_get() to retrieve
	a single system setting.

	* gdk/x11/gdkevents-x11.c: Bridge gdk_setting_get() and GdkEventSetting
	to the draft XSETTINGS mechanism.

	* gdk/x11/xsettings-{common,client}.[ch]: Sample-implementation of
	XSETTINGS.

	* gtk/gtkmain.c gtk/gtksettings.[ch]: Propagate notification
	of GDK settings changes to the GtkSettings object.

	* gdk/gdkevents.[ch] gdk/gtk/gtksettings.c: Hook up the
	double-click-timeout property to GDK.

	* gdk/gdkcolor.[ch] gdk/gdkvisual.h gdk/gdkevent.[ch] gdk/gdkfont.[ch]:
	Define GDK boxed types here.

	* gdk/Makefile.am gdk/makeenums.pl: Generate source files
	gdk/gdkenumtypes.[ch] for enum definitions.

	* gtk/gtkcompat.h: Add defines for GTK_TYPE_GDK_*
	* gtk/gtk-boxed.defs: Comment out GDK types
	* gtk/gtktypeutils.h: Remove GDK types
	* gtk/Makefile.am: No longer scan GDK headers for enumerataions