Fix memory leak. gdk_event_put would make a copy of next_event, and

Fix memory leak. gdk_event_put would make a copy of next_event, and

1998-12-30  Miguel de Icaza  <miguel@nuclecu.unam.mx>

	* gtk/gtkmain.c (gtk_main_do_event): Fix memory leak.
	gdk_event_put would make a copy of next_event, and next_event was
	not being freed.