gst-libs/gst/xoverlay/xoverlay.*: Adding the _expose method to tell an overlay to redraw the image because it has bee...

Original commit message from CVS:
2004-02-04  Julien MOUTTE  <julien@moutte.net>

* gst-libs/gst/xoverlay/xoverlay.c: (gst_x_overlay_expose):
* gst-libs/gst/xoverlay/xoverlay.h: Adding the _expose method to tell
an overlay to redraw the image because it has been exposed.
* sys/ximage/ximagesink.c: (gst_ximagesink_ximage_destroy),
(gst_ximagesink_ximage_put), (gst_ximagesink_expose),
(gst_ximagesink_xoverlay_init), (gst_ximagesink_init):
* sys/ximage/ximagesink.h: Implement expose method from XOverlay
interface
* sys/xvimage/xvimagesink.c: (gst_xvimagesink_xvimage_destroy),
(gst_xvimagesink_xvimage_put), (gst_xvimagesink_expose),
(gst_xvimagesink_xoverlay_init), (gst_xvimagesink_init):
* sys/xvimage/xvimagesink.h: Implement expose method from XOverlay
interface