Removed our quitting logic from nautilus-application
	(where it was tied to nautilus-window closing) and added
	a more general mechanism in main.c - by which you can
	register any gtk object to keep the main event loop
	alive while the object is around. This, in turn, fixed
	a problem with the first-time-druid not causing nautilus
	to quit when it was cancel via the close box (bug 2211)
	and also a problem with nautilus quitting before you had
	a chance to see an error dialog (bug 1871). Also, added
	nautilus_main_event_loop_quit as the preferred way to
	cause nautilus to quit (as opposed to gtk_main_quit)

	* src/nautilus-application.c: (nautilus_application_startup),
	(nautilus_application_close_desktop),
	(nautilus_application_destroyed_window):
	* src/nautilus-application.h:
	* src/nautilus-first-time-druid.c: (druid_finished),
	(nautilus_first_time_druid_show):
	* src/nautilus-main.c: (nautilus_main_is_event_loop_needed),
	(nautilus_main_event_loop_unregister),
	(nautilus_main_event_loop_register),
	(nautilus_main_is_event_loop_mainstay),
	(nautilus_main_event_loop_quit), (main):
	* src/nautilus-main.h:
	* src/nautilus-shell.c: (corba_quit), (corba_restart):
	* src/nautilus-window-manage-views.c:
	(nautilus_window_end_location_change_callback):
	* src/nautilus-window.c: (nautilus_window_initialize):