sys/glsink/: Use new GstVideoFormat checked into -base. Add new glupload element...

sys/glsink/: Use new GstVideoFormat checked into -base.  Add new glupload element to upload raw video into a GLXPixbu...

Original commit message from CVS:
* sys/glsink/Makefile.am:
* sys/glsink/glimagesink.c:
* sys/glsink/glimagesink.h:
* sys/glsink/glvideo.c:
* sys/glsink/glvideo.h:
* sys/glsink/gstopengl.c:
* sys/glsink/gstglupload.c:
Use new GstVideoFormat checked into -base.  Add new glupload
element to upload raw video into a GLXPixbuf.  Untested.  Will
likely crash your motorcycle if you try it.
* sys/glsink/gstvideo-common.c:
* sys/glsink/gstvideo-common.h:
Remove.