Make bower release-able with grunt tasks

This PR includes changes necessary to distribute ngActiveResource via Bower. The only caveat is that `async` needs to be manually added as a script tag for those that are using grunt to build their bower script tags.

I have added several grunt modules pertaining to the building of distribution scripts both minified and unminified. You may want to consider removing `node_modules` and `bower_components` as they will be downloaded with the release and the `bower_component` dependencies will be downloaded based on the `bower.json` dependency list.