sys/ximage/ximagesink.*: Refactoring of ximagesink.

sys/ximage/ximagesink.*: Refactoring of ximagesink.

Original commit message from CVS:
2005-11-18  Julien MOUTTE  <julien@moutte.net>

* sys/ximage/ximagesink.c: (gst_ximage_buffer_finalize),
(gst_ximagesink_check_xshm_calls), (gst_ximagesink_ximage_new),
(gst_ximagesink_ximage_destroy),
(gst_ximagesink_xwindow_draw_borders),
(gst_ximagesink_ximage_put),
(gst_ximagesink_xwindow_new),
(gst_ximagesink_xwindow_update_geometry),
(gst_ximagesink_handle_xevents), (gst_ximagesink_event_thread),
(gst_ximagesink_xcontext_get), (gst_ximagesink_xcontext_clear),
(gst_ximagesink_bufferpool_clear), (gst_ximagesink_getcaps),
(gst_ximagesink_setcaps), (gst_ximagesink_change_state),
(gst_ximagesink_show_frame), (gst_ximagesink_buffer_alloc),
(gst_ximagesink_navigation_send_event),
(gst_ximagesink_set_xwindow_id), (gst_ximagesink_expose),
(gst_ximagesink_set_property), (gst_ximagesink_get_property),
(gst_ximagesink_finalize), (gst_ximagesink_init),
(gst_ximagesink_class_init):
* sys/ximage/ximagesink.h: Refactoring of ximagesink.
This new version brings correct software scaling, non flickering
window while resizing, pixel aspect ratio handling, usage of
hardware buffer pools, out of data flow event thread for
navigation and handling of expose events even when being PAUSED,
a new property to keep video aspect ratio when resizing, etc...