sys/ximage/ximagesink.c: Better X events handling, only take the latest events for configure and motion.

Original commit message from CVS:
2004-02-02  Julien MOUTTE  <julien@moutte.net>

* sys/ximage/ximagesink.c: (gst_ximagesink_renegotiate_size),
(gst_ximagesink_handle_xevents): Better X events handling, only take
the latest events for configure and motion.
* sys/xvimage/xvimagesink.c: (gst_xvimagesink_handle_xevents): same.