Attempt at Chrome support:
- Chrome <-> Chrome datachannels work
- Firefox <-> Chrome datachannels do not work
Interop details:
- usage of adapter.js from http://code.google.com/p/webrtc-samples/source/browse/trunk/apprtc/js/adapter.js
- support of ice candidate messages through the broker

also fixed bad sdp transmission in the broker
also fixed minor indent and import issues