Cairomm-1.10.0 stopped linking correctly and started missing
includes after the Homebrew-0.9.2, the cairo, and the pixman
changes. Add `depends_on :x11` and fix all the problems.
Tested on Lion using clang and llvm from XCode-4.3.3.
Fixes # 13313
ClosesHomebrew/homebrew#13333.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>
Eventually we should try to just get this from XQuartz, but for now
let's depend on cairo for consistency.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>