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
The string is used in two places and my recommendation is that both strings, `RJS_OPTIMIZATION_ENABLED` and `RJS_OUTPUT_DIR`, be stored in a variable and referenced in both locations used.  Is there a reason not to?