have a dummy case GDK_OWNER_CHANGE in switch statements to avoid gcc

have a dummy case GDK_OWNER_CHANGE in switch statements to avoid gcc

Fri Jul  9 15:33:55 2004  Manish Singh  <yosh@gimp.org>

        * gdk/gdkevents.c: have a dummy case GDK_OWNER_CHANGE in switch
        statements to avoid gcc warnings about not all enum values handled.

        * gdk/x11/gdkdisplay-x11.c (gdk_display_open): ignore should live in
        #ifdef HAVE_XFIXES.