Adds in code to handle require transformations.

- Added in a context module to handle module registration and lookups.
- Created a higher level abstraction to facilitate RequrireJS
  optimization.
- Modified the transformation code to handle the `require` conversion.
- Upgraded utils to have a `once` method to call functions a single
  time.
- Modified the package.json to point to the new abstraction.
Transform require params to use valid identifers.

- Fixes the broken test (sort-of) by correcting how parameters are
  assigned.
- The test still fails, as we need to prime the module context with a
  mock first.