Aiortc-datachannel-only

-----

Data channels
.............

* Revert making RTCDataChannel.send a coroutine.

-----

Media
.....

* Enable post-processing in VP8 decoder to remove (macro) blocks.

* Set target bitrate for VP8 encoder to 900kbps.

* Re-create VP8 encoder if frame size changes.

* Implement jitter estimation for RTCP reports.

* Avoid overflowing the DLSR field for RTCP reports.

* Raise video jitter buffer size.

Data channels
.............

* BREAKING CHANGE: make RTCDataChannel.send a coroutine.

* Support spec-compliant SDP format for datachannels, as used in Firefox 63.

* Never send a negative advertised_cwnd.

Examples
........

* `datachannel-filexfer`: new example for file transfer over a data channel.

* `datachannel-vpn`: new example for a VPN over a data channel.

* `server`: make it possible to select video resolution.

-----

Media
.....

* Align VP8 settings with those used by WebRTC project, which greatly improves
video quality.

* Send RTCP source description, sender report, receiver report and bye packets.

Examples
........

* `server`:

- make it possible to not transform video at all.

- allow video display to be up to 1280px wide.

* `videostream-cli`:

- fix Python 3.5 compatibility

Miscellaneous
.............

* Delay logging string interpolation to reduce cost of packet logging in
non-verbose mode.

-----

Peer connection
...............

* Add :meth:`RTCPeerConnection.addIceCandidate()` method to handle trickled ICE candidates.

Media
.....

* Make stop() methods of :class:`aiortc.RTCRtpReceiver`, :class:`aiortc.RTCRtpSender`
and :class:`RTCRtpTransceiver` coroutines to enable clean shutdown.

Data channels
.............

* Clean up :class:`aiortc.RTCDataChannel` shutdown sequence.

* Support receiving an SCTP `RE-CONFIG` to raise number of inbound streams.

Examples
........

* `server`:

- perform some image processing using OpenCV.

- make it possible to disable data channels.

- make demo web interface more mobile-friendly.

* `apprtc`:

- automatically create a room if no room is specified on command line.

- handle `bye` command.

-----

Peer connection
...............

* Make it possible to specify one STUN server and / or one TURN server.

* Add `BUNDLE` support to use a single ICE/DTLS transport for multiple media.

* Move media encoding / decoding off the main thread.

Data channels
.............

* Use SCTP `ABORT` instead of `SHUTDOWN` when stopping :class:`aiortc.RTCSctpTransport`.

* Advertise support for SCTP `RE-CONFIG` extension.

* Make :class:`aiortc.RTCDataChannel` emit `open` and `close` events.

Examples
........

* Add an example of how to connect to appr.tc.

* Capture audio frames to a WAV file in server example.

* Show datachannel open / close events in server example.