[MOVED FROM GOOD] Add directdrawsink to build and dist it, so it gets built when...

[MOVED FROM GOOD] Add directdrawsink to build and dist it, so it gets built when compiling with MingW on win32 and the required headers...

Original commit message from CVS:
Patch by: Vincent Torri  <vtorri at univ-evry fr>
* configure.ac:
* sys/Makefile.am:
* sys/directdraw/Makefile.am:
Add directdrawsink to build and dist it, so it gets built when
compiling with MingW on win32 and the required headers and libraries
are available (fixes: #392313).
* sys/directdraw/gstdirectdrawsink.c:
(gst_directdrawsink_center_rect), (gst_directdrawsink_show_frame),
(gst_directdrawsink_setup_ddraw),
(gst_directdrawsink_surface_create):
Comment out some unused things and fix some printf format issues in
order to avoid warnings when buildling with MingW (#392313).