Parsing of MP4 files works
Merge pull request #89 from ismcodes/master

Optional Downvotes added.
Merge branch 'master' into mp4support
Merge pull request #91 from noidedmedia/mp4support

Added support for MP4 files.
Update wav_head_info.rb

Accidentally put experimental stuff in my branch when I committed it. Please change this because it doesn't work as far as I know. Sorry!
Merge pull request #92 from ismcodes/patch-2

Remove accidental issues in previous pull request.