Introducing event system.
Events can be bound to the RTC object itself or to an instance of it. Events are not shared accross instances or the global RTC object.
Add RTC._listeners
Add RTC.bind( type, listener )
Add RTC.fire( event, data )
onLocalStreamAdded, onIncoming, onRemoteHangup and onReady now aliases to this.bind( … )
set chaining right for some methods.
API change in onReady and onLocalStreamAdded.