Fixed discrepant versions

Fix for #19.  I probably got a bit carried away...

* Read current version from `package.json` instead of `VERSION`.  Deleted `VERSION`.
* Use grunt concat and uglify banners to set version
* Use grunt-bumpup to increment version
* Added `Makefile` to streamline build lifecylce tasks
* Corrected version to 0.3.0 from 0.2.1