NSImage Support + Sample Mac App

Please enjoy the comically terrible sample Mac App I hacked together. If there are Mac developers watching this repo, any suggestions for making it less comically terrible would be much appreciated.

Under our [framework code standards](https://github.com/vokalinteractive/Coding-Standards/blob/master/Frameworks/WORKING_WITH_FRAMEWORKS.md) this would constitute a major update, so this pull request will remain open for comment for three business days (EOD Tuesday, 1/28 since I'm submitting so late on Thursday) and requires at least 2 "looks good to me" comments from Vokal iOS engineers to get merged. 

This pull request would address issue #3 - Mac App support.