Got something working with mounting evergreen in a Rails 2.3 app.

Howdy, y'all. Thanks for evergreen! Writing my specs in coffeescript brings a smile to my face every time. 

Anyways, here's a proof-of-concept of mounting evergreen in a Rails 2.3 app. I'm no rack expert, so I'm sure there's a much cleaner way to accomplish what I've cludged together in this commit, but I wanted to at least get the conversation started on getting something like this merged in. Thoughts?