Support "optional" bindings. If a binding signal has a boolean return

Support "optional" bindings. If a binding signal has a boolean return

Wed Jan 16 19:23:04 2002  Owen Taylor  <otaylor@redhat.com>

	* gtk/gtkbindings.c (gtk_binding_entry_activate):
	Support "optional" bindings. If a binding signal
	has a boolean return value, and returns FALSE it
	is as if it didn't exist all.

	* gtk/gtkbindings.c (binding_compose_params): Switch
	over to GValue.

	* gtk/gtknotebook.[ch]: Make the select_page() and
	change_current_page() signals only take effect when
	the focus is on the tab area so that key presses
	in children pass up to the toplevel correctly.