Remove Lists

The list structure is holding us back for several reasons:

- It is too complicated for users to learn -- they're more likely to 'rage quit' than to learn to use them effectively
- It has made the code too complicated -- There's a lot of duplication, unnecessary abstraction, and flat-out broken code
- It takes away from our ability to test effectively -- giving control over website content to the users means we have less control over what is presented in a test.
- It will take too long for new developers, especially those without too much Ruby on Rails experience, to fully grok the class and db structures of the list

Having such a complicated structure so close to the core of the application is a breeding ground for bugs -- and some have already arisen.