Issue 1

Migrated the code to work with Grunt 0.4.0 (to be relased today) by:
- Renamed grunt.js to Gruntfile.js
- Adjusted the Gruntfile for 0.4.0 compatibility
- Adding grunt-contrib-jshint as a development dependency to make the Gruntfile in this repo work again
- Making the "zipstream" Helper a method of the exports, because Helpers have been removed.

If you have any questions, I'd be happy to help.