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 istance 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 documenation and inline comments throughout.
Merge pull request #8 from eojthebrave/eojthebrave-refactor_document_cwfm.room.js

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