Raised core revision

Ignore-this: ae334de02a5da541c6e3d13c86696779

darcs-hash:20130603092703-56b4d-e83d0c9b9f319939ff58f019156a8d016a07f26d
Fixed compilation with Xcode >= 4.6

Ignore-this: 3cd123c9d8052ea02b74eebcc45f38f9

In Xcode >= 4.6 and OSX 10.8 the SDKs are no longer located in /Developer/SDks,
they are located inside the XCode.app application.

darcs-hash:20130603092819-56b4d-4456cd7eb15ca3cf2c1c5a979bad1f1effb63231