After Social.localUser.Authenticate fails, it should output/return why it failed, for example it might be necessary to react differently to situation when the user doesn't login to the Game Center by exiting login window, than when Authenticate fails for other reasons. But because it only returns a bool it's impossible to determine the actual reason.

To Reproduce:

1. Just build the scene 'TestScene(Standalone)' from the attached project.
2. When Authenticate there is now way to determine why exactly did it fail.