- rendering helpers moved to their own file (separate from response helpers)
- create a unified render helper instead of "buffered_render_basic_X" and "buffered_render_tweet_X"
- this helper takes 2 data objects: one with global data (tweet trove, logged in user, etc) and one page-specific
- this lets us remove the disgusting interface type
- modify the User List template to use UserIDs indexing into a global data object instead of a list of Users
- Chat list previews look a bit nicer, and display the time of last message
- Chat messages show sent_at time
- Messages with line breaks will actually display as paragraphs now
- Misc spacing improvements
- BUGFIX: fix preview DB query crashing if there's no messages in a chat
