Fixing #38, and may be #39

Channel presence in "socket.io over node.js" can be detected like this:

function testChannelPresence(channel) {
var socket = io.connect('/');

socket.on('presence', function (isChannelPresent) {
console.log('is channel present', isChannelPresent);
if (!isChannelPresent) playRoleOfSessionInitiator();
});

socket.emit('presence', channel);
}
testChannelPresence('default-channel');

Demo: http://webrtc-signaling.jit.su/RTCMultiConnection

Socket.io over Node.js source code:

https://github.com/muaz-khan/WebRTC-Experiment/tree/master/socketio-over-nodejs