Re: Issue 174: When is an IceGatherer allowed to prune host, reflexive and relay candidates?

This issue was originally filed by Robin Raymond:
https://github.com/openpeer/ortc/issues/174

We had originally kicked around the idea of a timer.  Robin is now proposing to add an optional RTCIceGatherer to the RTCIceTransport constructor.
This would allow the IceGatherer to know what IceTransports it is associated with, and track their states.


Proposal:
In Section 3, add the following WebIDL:
[Constructor(optional RTCIceGatherer gatherer)]

In Section 3.3.1 modify the text to:
The iceGatherer attribute is set to the value of gatherer if passed in the constructor or in the latest call to start().

Add to Section 5.1:
The RTCIceGatherer does not prune local candidates until at least one RTCIceTransport object has become associated and all associated RTCIceTransport objects are in the "completed" or "disconnected" state.