[WIP] MOAITest for iOS

I made some changes to get the MOAITest class to work on the iOS system.  So far, I have only tested it on Xcode's iOS simulator. I haven't set up a formal example folder in the (moai-dev)/samples directory yet.  MOAITest works with certain tests in the (moai-dev)/test folder, but I have not tried them all, especially the ones that create image files for the staging.

Currently, the 'setResultsFile' needs to be called with a valid file location in order for the testing details to be printed to the console.  Also, the file gets rewritten to zero bytes after running it.