Fixed Issued 69, plugin now works with Xcode 6.0.1

Updated project settings, turned off debug user interface setting in
scheme and removed and readded XCFPreferencesWindowController.xib
resource. It was not be copied to the plugin’s resource folder
Merge pull request #70 from SpottedRabbit/master

Fixed Issued 69, plugin now works with Xcode 6.0.1