Place a manual redirect on windows on xwl_realize_window() and remove
it on xwl_unrealize_window() to avoid the X11 window manager removing
its redirect before Xwayland has unrealized the window (e.g. if the X11
window manager has terminated unexpectedly)
Suggested by Daniel Stone <daniel@fooishbar.org>
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>