RequireJS conversion

This branch incorporates two changes related to RequireJS:

1. Converts all Lavaca modules to use AMD format.  The app/ base application has also been converted and is working properly.

2. Modifies the Grunt build to incorporate the RequireJS optimizer (in both build and jasmine-related tasks).  **Grunt 0.4** was released during development of this branch, so new tasks and the Gruntfile are written to use Grunt 0.4 (perhaps belongs in a separate branch...).