Homebrew/homebrew — pull request #28096 by jacknagel (2014-04-03 01:08:03+00:00)
Title: Get rid of "use X11 if it's installed" deps

I want to get rid of these because:

* they are more confusing than a plain optional/recommend dep
* they can't be tracked reliably because of the conditional
* they present a roadblock to bottling some things
* the first time `MacOS::X11.installed?` is called, we shell out to `mdfind` and `mdls`, which makes formula loading slower than it needs to be