chore(index): remove dead comments to reduce clutter
feat(*): add namespaces to used by call and chat connection

Added namespaces:
- /webrtc/call
- /webrtc/chat

Others:
- Remove dead comments to reduce clutter
- Replace mocha test runner with grunt-mocha-cli
refactor(signaling server): use call namespace to send ice candidates

Removed listener:
- 'chat:video' is removed from the global namespace

Added listener:
- 'calling' listener is use to replace the 'chat:video' and it's available under the call namespace

Notes:
- This 'calling' event name is used by the PeerConnection.js to send ice candidates to the other peer
fix(PeerConnection): remove undefined timers variable

Error log:
- Uncaught ReferenceError: timers is not defined
fix(PeerConnection): fix Uncaught ReferenceError: his is not defined
fix(user controller): fix the uri
refactor(room controller): connect to the call space

Breaking changes:
- The remote video is still not showing up the application
fix(signaling server): move the calling listener to global space

Notes:
- Somehow, even we pass the call space to PeerConnection.js constructor, the received 'calling' event is always coming from the global space

Others:
- minor changes on chat:id listener
chore(room controller): add comments on where the roomId is defined from
chore(room controller): remove some dead DOM manipulation codes
Merge branch 'refactor-signaling-server'