Updates to match changes in React API

Hi @banyan! I've made some changes to match the current state of React (matching v0.12.x). I'd love your thoughts! The biggest change as far as I can tell is bringing it in line with Brunch's plugin specifications. 

- Updated to support the updated API for React (adopting the factory
  pattern), and likewise removing aspects of this compiler that were not
  relevant to coffeescript (such as ECMAScript Harmony support or the
  Pragma header)
- Updated package.json version to match Brunch's plugin specifications
  (following the minor versions).
- Removed tests that weren't relevant to Coffeescript compilation (or because of
  changes to the React API).