configure: add support for specifying a branch to use.

This is intended for use in releases.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36946 b3059339-0415-0410-9bf9-f77b7e298cf2
Normalize 8-bit format "endianness".

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36947 b3059339-0415-0410-9bf9-f77b7e298cf2
ao_sndio: simplify, don't care about 8-bit endianness.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36948 b3059339-0415-0410-9bf9-f77b7e298cf2
Use select_audio/select_video to disable unused streams.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36949 b3059339-0415-0410-9bf9-f77b7e298cf2
demux_mpg: search longer for selected stream.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36950 b3059339-0415-0410-9bf9-f77b7e298cf2
Fix previous sync error



git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36951 b3059339-0415-0410-9bf9-f77b7e298cf2
For -dump* to retry once of it reached EOF before writing anything.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36952 b3059339-0415-0410-9bf9-f77b7e298cf2