finishing update counter patch

[Havoc Pennington <hp redhat com>]

Hi,

I'd like to get the update counter patch into CVS:

  http://mail.gnome.org/archives/wm-spec-list/2002-December/msg00023.html

The way the patch currently works is that it increments the update
counter:

 - anytime we process updates
 - in an idle after receiving a configure notify 
   (normally we'd process updates before the idle runs, 
    I think is the idea, but we need to guarantee 
    we update the counter even if no updates get processed)

The patch is clearer if you pretend _gdk_window_must_notify_updated
is called _gdk_window_queue_notify_updated().

Does the basic approach of the patch look right, or should 
I implement it differently?

Right now this patch is metacity-specific, but I think it's worth
putting in anyway. Can always change it later, it's not anything that
creates ABI or that needs to be frozen. There wasn't any initial
interest on wm-spec-list in adding the hint to the spec.

Havoc