Bower prepublish script

So I screwed up and forgot to fix up the gitignore situation and add the prepublish script to package.json. Now, whenever you run `npm publish`, the bower package will be automatically built and tagged as well.

You'll also need to run `bower register waterline-criteria git://github.com/balderdashy/waterline-criteria.git` **once** before your next `npm publish`. THEN everything should be peachy! Hit me up in IRC if you need any clarification.