Databased

Pull in all the changes I've done on tabular diffing.

If you're wondering why you're seeing it's because you haven't given me write access to this repo. That is okay, actually, because it forces us to be better about our code cycle. From now on, I'll do work at https://github.com/kousu/modex, and send pull requests for you to review before merging. This is the One True Github Way.