Added support for AMD and NodeJS

Hi,

I'm using your great extension in my project with browserify and I need it to be an npm package, so I added support for node.js and AMD. I think it will be useful for others.
Also I've added package.json, so it would be great if you can publish your library to npm repository

I've tried to run your tests, but it seems that you're using some old version of grunt, so I failed to run them. But I didn't changed your code, I've just wrapped it with another function that prepares dependencies in different ways depending on environment

Thank you for your great Backbone extension and don't forget to publish it to nom repository 

Sincerely,
Anthony