mozilla/servo — pull request #2716 by Manishearth (2014-06-25 09:24:00+00:00)
Title: Ignore dirty submodules for fontconfig and libexpat

Sumbodules which use automatic gitignore generation create a "dirty submodule" change, which can accidentally be committed if you're fond of `git commit -a` et cetera.

This will ignore dirty submodule changes for these, clearing up `git status` and letting you use `git commit -a` with impunity.