Studio accidentally renamed some of the javadoc to reflect the new
vorbis module. Revert it to the dev javadoc, as the ExoPlayer devs
don't update the javadoc until a release.
Refactor the overall module to place the unified vorbis tags into a
single package called `vorbis`. Also re-intoduce the vorbis tags
in their original `flac` module, but deprecate them.
