The source from this directory was copied from the libvorbis
subversion repository using the update.sh script. The only changes
made were those applied by update.sh and the addition/update of
Makefile.in and moz.build files for the Mozilla build system.

The upstream version used was libvorbis 1.3.5.
https://svn.xiph.org/tags/vorbis/libvorbis-1.3.5@19464

Some files are renamed during the copy to prevent clashes with object
file names with other Mozilla libraries.