Tue Jan 12 13:47:07 1999  Tim Janik  <timj@gtk.org>

        * reworked the redrawing heuristics somewhat, this fixed a bunch of
        existing redrawing problems and majorly reduces overall redrawing needs
        during normal operation. basically we now only queue redraws when
        neccessary and much rely on the draw_area coalescing code in gtkwidget.c
        to optimize the queued portions. widgets will now upon reallocation only
        get redrawed if their allocation has changed. upon hide/show only the
        area allocated by the child will be queued for the parent, this has the
        side effect that parents which change their appearance in dependance on
        the numer of visible children have to keep track of their children's
        visiblity and eventually fully redraw themselves. this is a minor
        constrain with great benefits in terms of redraw reduction, and only got
        triggered by the noteb...