Set keyword substitution on the 5.1 mode files.


git-svn-id: http://svn.xiph.org/trunk/vorbis@19013 0101bb08-14d6-0310-b084-bc0e0c8e3800
Add license header and turn on keyword substitution for 5.1 codebook.


git-svn-id: http://svn.xiph.org/trunk/vorbis@19014 0101bb08-14d6-0310-b084-bc0e0c8e3800
Enable keyword substitution on remaining files with $Id$ lines.


git-svn-id: http://svn.xiph.org/trunk/vorbis@19015 0101bb08-14d6-0310-b084-bc0e0c8e3800