Implementation of the patiencediff algorithm, as first described by Bram
Cohen: https://bramcohen.livejournal.com/73318.html

Like Python's difflib, this module provides both a convenience
unified_diff function for the generation of unified diffs of text files
as well as a SequenceMatcher that can be used on arbitrary lists.

Patiencediff provides a good balance of performance, nice output for
humans, and implementation simplicity.

The code in this package was extracted from the Bazaar code base.