Expose this error so pion/webrtc can handle gracefully.
rfc8839#section-5.1 specifies that a WebRTC Agent MUST
ignore any name/value pairs it doesn't understand.
Relates to pion/webrtc#1949
The webrtc-stats spec defines this field as:
> It is the protocol used by the endpoint to communicate with the TURN
> server. This is only present for local candidates. Valid values are
> "udp", "tcp", or "tls".
https://w3.org/TR/webrtc-stats/#dom-rtcicecandidatestats-relayprotocol
This change will allow us to have custom logic and members
per interface type. Relay candidates will have a completely different
read loop, and candidate specific state.
Relates to #47
Some constants were being incorrectly generated using 2^N (XOR)
instead of 1 << N. This resulted in incorrect candidate priorities
being used to evaluate candidate pairs.
Resolves#14.
