Packaging RequireJS Dependencies

RequireJS is used normally (dependencies loaded individually) in development.
Flipping the RJS_OPTIMIZATION_ENABLED bit and running r.js (before compress)
will result in all dependencies being bundled and downloaded together.

@rocha @dsjen @andy-armstrong
It might be nice to pull `RJS_OPTIMIZATION_ENABLED` and `RJS_OUTPUT_DIR` into variables since it's used a few times.