Fix up project to get dynamic cell heights working

I made some changes and got everything working (at least as far as I can see).

I removed the use of the prototype cell from the Storyboard, as I've only found it to add confusion and problems, especially when you already had 95% of the work being done in code anyways.

I wrote inline comments on some of the important bits, but please let me me know if you have any other questions or want further explanation of whatI did!