Generating local parameters

[steveanton]

When does the RTCIceTransport generate its local parameters (ufrag/pwd)?

Ideas:

• At creation time. This means getLocalParameters() will never return null (it's allowed to in the WebRTC-PC specification).
• Regenerate them every time gather() is called after the first time.

[aboba]

In ORTC getLocalParameters() never returns null (the specification doesn't say whether the local parameters are generated when the RTCIceGatherer is constructed or when getLocalParameters is called).

Let's discuss what happens when gather() is called multiple times in Issue #7