This is a copy of the Xcode Manipulation API
https://bitbucket.org/Unity-Technologies/xcodeapi/overview

This is already packed inside Unity under the UnityEditor.IOS.XCode namespace,
but I'm including here as well because the version that comes with unity doesn't handle 
localized files.
This copy includes the pullrequest #13 (https://bitbucket.org/Unity-Technologies/xcodeapi/pull-requests/13/creation-of-variantgroup-and/diff)

Hopefully that will be integrated in Unity soon, but until then, I will be including this files here!