Added nice styling of diffs in the FileDiff admin UI.

Review Request #3817 — Created Jan. 30, 2013 and submitted — Latest diff uploaded

Information

Review Board
master

Reviewers

Added nice styling of diffs in the FileDiff admin UI.

The FileDiff admin UI previously just showed diffs with no whitespace
preservation, which was useless. We now style it with Pygments, which is
nicer to look at.
Tested with some diffs. They looked nice.