NOTE: this code is a work in progress. However the goal is to create a
diff program that works better on text files containing prose than the
traditional Unix line-based diff.

Update 2014-02-14: I used this code when I was running the ill fated Code
Quarterly. It was incredibly useful to be able to take a text file from an
author, edit it to my heart's content, and then generate a diff that was
even better than what Word track changes could show since it shows sections
that are moved and also edited in a sane way.

The algorithm is not speedy as it does a N^2 comparison of all the paragraphs
that differ at all between the two versions so it's not great for realtime
but for generating a diff offline and then putting on the web for an author
to look at, it was quite nice.