Add comments so this can go in marmalade

These are needed to add this to MELPA.  I've already made a pull request there: https://github.com/milkypostman/melpa/pull/1265, hope that's ok :)

More info on MELPA: http://melpa.milkbox.net/

More info on the format:
http://marmalade-repo.org/doc-files/package.5.html