Content API

[drusepth]

We should add an auth token column to users and assign everyone a random token that allows them to authenticate over an API to fetch their content.

• [x] Add auth token to users
• [x] Generate random tokens for all existing users
• [x] Set randomized tokens on user creation
• [ ] Add API endpoints for universes, characters, locations, and items that return each by ID, requiring the owner's auth token if they are private
• [ ] Add API endpoints to list a user's content (universes/characters/locations/items) ids+names+descriptions, serving back all content if their auth token is passed, and only their private content otherwise.

This API would go a long way to developing apps on top of the notebook, like #54