Replaced custom make with Grunt build system

RaphaelJS was using a custom make file. It does the job but it's reinventing the wheel and makes it harder to add things like unit-tests and linting. Replacing it with [GruntJS](http://gruntjs.com/) (which is pulled down by NPM during `npm install`) leaves the project slightly cleaner and more extensible for build-steps. Only build change is running `grunt` instead of `make`.

With a simple addition I could ad [Travis-CI](travis-ci.org/) support that checks all pull requests that they follow the coding standards and any eventual unit tests are passing.