Update Build process

_Moving from #38 against v0.5 branch_

Updates to Grunt build process to use latest version of tooling. Slight reorg of files

**Changes:**
- Rewrote Gruntfile.js
  - ignoring jshint for now, there will be a bigger PR for that
- Updated package.json dependencies
- Moved processing files to `src/build` (mimics backbone.marionette structure)
- Some trailing whitespace was trimmed
- Adds source maps alongside existing built files