R1:6ea1b8df9bbb

Colorize filetree for adds, moves, and deletes

Summary: See PHI356. Makes it easier to pick out change types in the filetree view in Differential.

Test Plan: Created a diff with adds, copies, moves, deletions, and binary files. Viewed in Differential, had an easier time picking stuff out.

Differential Revision: https://secure.phabricator.com/D19040