Grunt Build

Created a Grunt build process to replace the current `watch` file in the `css/` folder, allowing it to work on both Windows and Unix systems.

In my opinion the Grunt process should be moved to [inuit.css](http://github.com/csswizardry/inuit.css) to create a `build` folder which will contain `style.min.css`, allowing users to link to the raw source of this file in prototypes. Just an idea!

Also allows for linting, concating, adding banners, etc, during the build. I'll happily keep on top of this if you need someone to take care of it.