If the old_geometry coordinates were saved while the window
was in another xinerama head, use current coordinates as
the old ones to avoid making the window jump heads when
un-maximizing it.
When a maximized window is resized (either using wmaker or because the
application changed the window size), and you want to maximize it again,
you first have to unmaximize it (because wmaker thinks the window is still
maximized), and only then you can maximize it. The following patch
corrects this behaviour.
Nicolas Bonifas