Add audio/video pause/resume and mute to the RtcommEndpoint.

[swgraham]

Add audio/video pause/resume and mute to the RtcommEndpoint.

[swgraham]

Resolved in release/v1.0.0-beta.14 as noted above.

Added to the RtcommEndpoint.webrtc:

mute()
unmute()

Added several boolean checks:
isMuted() [return if stream is muted]

isSendingAudio()/isReceivingAudio();
isSendingVideo()/isReceivingVideo();
The above check that there is an audio or video track and if it is 'enabled'

Added an event:
'webrtc:remotemuted' to indicate that the remote peer muted the stream. This is useful for changing the display.

We also send a MESSAGE of 'webrtc' protocol that contains payload indicating what was muted for the peer.