XCode project tidied up, tests running in AppCode again.
Added CCLightNode-Prefix.pch file as every other node had that one themselves.
Added xcscheme for AppCode tests. AppCode needs a separate scheme. Does not interfere with XCode.
Merge pull request #1238 from NickyWeber/bugfix/TestsAppCode

XCode project tidied up, tests running in AppCode again.