Refactor cwfm.room.js, remove duplicate/faulty code. Add documentation.

Refactor cwfm.room.js, remove duplicate/faulty code. Add documentation.
    
- Resolves #4 by removing the addMe() function which didn't check to see if a user was already in the djs list before adding them.
- Resolves #5 by removing the removeMe() function which only removed one instance of the dj that was added to the list by the addMe() function.
- In both cases these calls are replaced with calls to the addUser() and removeUser() functions.
- Improves documentation and inline comments throughout.