Replace Makefile with GruntJS

I have replaced the makefile with GruntJS. It supports all the previous commands and more.

## Commands

### Public, as per Readme:
`grunt` - takes the role of make, and does the basic package

`grunt test` - runs jshint and qunit

`grunt watch` - sets up a watch for LESS changes

### Private, as I found in the Makefile:
`grunt cleanit` - cleans the /bootstrap directory

`grunt bootstrap` - copies files to /bootstrap directory

`grunt gh-pages` - creates a sibling folder with docs etc

### New, bonus:
`grunt travis` - for Travis CI, runs the same thing as `grunt test`

All grunt tasks can be run separately. Such as `grunt qunit` etc.

## Note
I'm not an expert on this and there are a few things I was wondering about, so I'd like someone that knows more about what to expect from the build tasks to try this out. Let me know if you face any issues and I'll fix it.