mxcl/homebrew — pull request #13457 by nolta (2012-07-17 23:14:16+00:00)
Title: restore x11 to pkg-config's list of default paths

You used to be able to install matplotlib with

```
$ brew install pkg-config
$ easy_install matplotlib
```

But 63415cc broke this, by removing `/usr/X11/lib/pkgconfig` from pkg-config's list of default paths. Setting `PKG_CONFIG_PATH` doesn't help, due to a bug in matplotlib's makefiles.