creating an RTPSender with a track whose readyState is 'ended'

[fippo]

When attempting to create an RTPSender with a track whose readyState is 'ended' (e.g. because track.stop() has been called or the user unplugged the webcam) what should happen?

Since that state can't be left (see http://w3c.github.io/mediacapture-main/#methods-1) it does not seem useful to 'send' this track to the remote peer.

This affects two sections in the spec, first the constructor @ http://ortc.org/wp-content/uploads/2015/10/ortc.html#rtcrtpsender-operation*
I would propose the following change:
If an attempt is made to construct an RTCRtpSender object with transport.state or rtcpTransport.state "closed" or the track.readyState is "ended", throw an InvalidStateError exception.

Second, the setTrack method @ http://ortc.org/wp-content/uploads/2015/10/ortc.html#methods-3
How about this for the new step 3.2 before the current step 3.2?
If withTrack.readyState is "ended", then reject p with ToBeDefinedMediaStreamTrackError and abort these steps.