Grunting

Replaced current build process with [grunt](http://gruntjs.com) and the [tap](https://github.com/isaacs/node-tap) test framework has been replaced by [nodeunit](https://github.com/caolan/nodeunit).

Also, [CoffeeScript](http://coffeescript.org) has been removed as a dependency as it was never actually required to run the library as it was being pre-compiled to JavaScript.