Convert to Grunt Build Process

Introduced grunt and some plugins to replace the existing cakefile.

Now using a require.js task instead of a custom building file.  Moved
most of the Cakefile logic into the lib/build/index.coffee file and
converted it to custom grunt tasks.

Added verification of built data files.

Added masthead with version and license information to each built file.
Add lint validation to testing
Update README with grunt directions
Merge pull request #33 from sproutsocial/gruntRefactor

Grunt refactor and linting