Fixed an issue on Xcode Version 6.2 (6C86e) where the MacTypes.h header ...

...file was referred to with an absolute path which does not exist on disk

This was the issue:

![screen shot 2014-12-09 at 10 36 17](https://cloud.githubusercontent.com/assets/759524/5355051/7a3253ec-7f8f-11e4-8da9-e2650ae6dbde.png)