Fully localized!

This produces lang_region/whatever.js files in our builds.

I didn't have another language to test with, so I faked one: We've also got [pseudo-localization](http://en.wikipedia.org/wiki/Pseudolocalization) builds!

Just add `locale=en_us` to the dev query params in the dev server (the index links do this already)

On the Dashboard side, we need to change two paths: vendor.js and $app.js to include the locale in the filename.