Use grunt mocha test to run mocha.

This cleans up the package.json script a bit. Grunt-mocha-tests
automatically does things for us like catching assertions that
would normally be uncaught so that our test runner doesn't
explode at any point.
Update cue2json.js documentation.

Cue2json.js now uses dev builds instead of dists
to run it.
Make build banners more detailed.

It would be helpful to know the version that was built, not
just the date it was built on.