ic-diff

- http://www.jefftk.com/icdiff
- Couldn't find a version in the `ic-diff` repo, so I just used 1.0.0.
This isn't needed: http://bot.brew.sh/job/Homebrew%20Pull%20Requests/18085/version=yosemite/testReport/junit/brew-test-bot/yosemite/audit_icdiff/