support node require()

hey!

I added a bit so this works in node & published it to npm.
this is useful, because it's very convienient to bundle client side libs with something like 
https://github.com/substack/node-browserify

If you start doing node.js, ping me, and i'll make you the owner of the module.

mainly, I'm just making this pull request to let you know I've done this.

cheers, and thanks for writing exactly the module I was looking for!