Feature request: allow proxy to send public IP and port to client

[DavidSchinazi]

From Peter Thatcher on the list:

To be more useful for WebRTC, it would be nice for the proxy to tell the client what IP and port it is exposing publically (much like TURN does). Then WebRTC (or ICE more generally) could signal that as an ICE candidate to the remote side. It could get around this using a STUN server, but that's slower and more clunky.