video output: support rotated movies

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
XCB/X11: reorient video

(Note that the pointer position is not reoriented, this comes with a
later patch in the series for all XCB video outputs.)

Modified-and-...
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>