It doesn't seem to work well.  In full-screen mode, newly-added windows don't
always properly resize to fill the screen, so they're not the same size as the
windows they're nominally tabbed with.  In non-full-screen mode, switching
between tabs sometimes causes the windows to grow in height each time.  Etc.
Signed-off-by: Ken Thomases <ken@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>