Task module response prototype

Setup table structure and restructured some task modules/forms to store student responses in a table consistently. This also allows the task content to be dynamically displayed and maintained more consistently, while allowing the creation and reuse of modules.
I think the json is a pretty nice idea just because it gives us pretty trivial polymorphism here without making new tables for each module. Since we aren't likely to query against the config individually, the downsides of a text blob are relatively small.