aviheader.h is totally correct. defining useless typedefs that can
conflict with other headers is bad practice. i don't like editing
mmreg.h but oh well... if you have a better fix, commit it! finally,
the fix in the ad_ and vd_ files seems totally correct.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@12357 b3059339-0415-0410-9bf9-f77b7e298cf2