Switch: Wrap API for performing delayed changes
Switch: Wrap API for performing delayed changes

	* Wrap set_state(bool) and get_state() methods, and ::state
	property.
	* Wrap "state-set" signal.

GNOME/gtkmm,GNOME/gtkmm,GNOME/gtkmm,johne53/MB3Gtkmm,GNOME/gtkmm,johne53/MB3Gtkmm,johne53/MB3Gtkmm