show current userlist / bind to username changes
Merge branch 'master' of https://github.com/TeamCocoDojo/cocodojo

* 'master' of https://github.com/TeamCocoDojo/cocodojo:
  fix remove issue due to objectID type
  use image for whiteboard button, and remove unused console.log
  fix conflict on _editor.js and syntax error on editor.js
  refactory drawing, and use meteor for sync
  implement syntax highlighting