add multiple inclusion guards to headers
Originally committed as revision 9345 to svn://svn.ffmpeg.org/ffmpeg/trunk
get rid of unused entries in the middle of xvmc_render struct,extensions are added to the end of the struct (avoids build issues on 64 bits platform)add osd extension to be used by mplayer (required by the resent changes in the build system)breaking the compability, thus bumping minor lavc version number...
Move xvmc_render.h to libavcodec where it belongs. Blessed by Ivan.
Originally committed as revision 7986 to svn://svn.ffmpeg.org/ffmpeg/trunk