ext/directfb/dfbvideosink.*: Now does clipping when surface is too small, handles upstream elements that are not call...

Original commit message from CVS:
2005-11-04  Julien MOUTTE  <julien@moutte.net>

* ext/directfb/dfbvideosink.c:
(gst_dfbvideosink_surface_create),
(gst_dfbvideosink_surface_destroy),
(gst_dfbvideosink_get_best_vmode), (gst_dfbvideosink_getcaps),
(gst_dfbvideosink_center_rect), (gst_dfbvideosink_show_frame),
(gst_dfbvideosink_buffer_alloc):
* ext/directfb/dfbvideosink.h: Now does clipping when surface
is too small, handles upstream elements that are not calling
gst_pad_alloc_buffer, fixes a lot of bugs.