gepr

OK. I changed it in my fork. Should I send another pull request?

No particular insights, since I'm not really competent with JavaScript. I had to muddle my way through. I can say that I much prefer it over CoffeeScript, though.

I've added explanatory comments to step(), declared myModel as var, and explained [un]happiness in a comment. Let me know if there's any other changes you'd like to see. I spent...