Before we computed DataChannel IDs before signaling, this
is incorrect because IDs must take into account if we are
running an DTLS Client or Server.
This updates the DataChannel ID generation code to take this
into account before generating a streamId.
Resolves#908
Instead of printing the error to stdout return the error to the user.
This may not be a hard error (as later certificates would have passed)
but it never is good to be in a state where you have certificates in a
broken state.
Resolves#586
Let's pull off the bandaid!
* Reduces studdering: webrtc.RTCTrack -> webrtc.Track
* Makes it easier to find types by editor autocomplete
* Makes code read more fluently (less repetition)
Since we're breaking the API in 2.0, our only chance to
do this is now.
Relates to #408
