implemented default handler for key-release events, which checks for

implemented default handler for key-release events, which checks for

Tue Jun 30 09:24:40 1998  Tim Janik  <timj@gtk.org>

        * gtk/gtkwidget.c (gtk_widget_real_key_release_event): implemented
        default handler for key-release events, which checks for activation
        of GDK_RELEASE_MASK key bindings.

        * gdk/gdktypes.h (enum): added GDK_RELEASE_MASK to GdkModifierType.