Add events for video, audio, and data.

[nsthorat]

This allows writing a relay without using ffmpeg (by using a client publisher to directly write to an RTMP endpoint by relaying this packet).

Example code for what this looks like:

const config = {
  rtmp: {
    port: 1935,
    chunk_size: 60000,
    gop_cache: true,
    ping: 30,
    ping_timeout: 60
  },
  http: {port: 8000, allow_origin: '*'},
  logType: 3
};

var nms = new NodeMediaServer(config);
nms.run();

// This is another NMS or RTMP server.
let rp = new NodeRtmpClient('rtmp://localhost:1936/live/stream');
rp.startPush();

nms.on('video', (id, response) => {
  console.log(
      'got packet for ', id, 'with timestamp', response.timestamp)
  rp.pushVideo(response.payload, response.timestamp);
});

[hthetiot]

@nsthorat you should not commit with message "save", instead you should write a description of the changes.
In 15 years of git, your the first person i see doing this, and god know i have see lame commit messages.

[nsthorat]

We have squash and merge for a reason, @hthetiot.