Ability to close rooms and delete them from the server

A few things need to be done for this:

- [X] Method for deleting rooms (along with associated rmessages
- [ ] Automatic closing of rooms after some set period (1 hour?)
- [ ] Ability for 'privileged' accounts (premium, admins) to keep rooms open indefinitely
- [ ] Generation of a HTML transcript upon closing rooms
- [ ] Somehow get user emails for transcripts