Add an 'overrideRedirect' flag to the window configuration section. For

Add an 'overrideRedirect' flag to the window configuration section.  For
multi-headed Gnome based linux systems, this provides an extra hint that we
really wish to open up our full screen window spanning all physical displays.
This works around a kink in the gnome window manager where it tries to "lie"
to applications about the full screen size assuming most applications don't
wish their windows to span multiple physical displays.