fix a few common stream/scuttlebutt gotchas

scuttlebutt_muxdemux_test.js

var MuxDemux = require('mux-demux');
var net = require('net');
var Model = require('scuttlebutt/model');

var aModel = new Model
var bModel = new Model

//the scuttlebutt's must have 1 stream per connection,
//therefore they must be created inside the server handler.

// Server
var server = new net.createServer(function (stream) {
    var mx = new MuxDemux
    mx.pipe(stream).pipe(mx)

   //the server side should listen on 'connect'
   mx.on('connection', function(stream) {
        if (stream.meta === 'channel1') {
            //scuttlebutt does a handshake, even if you only update one side.
            //so, you have to connect it duplex style.
            stream.pipe(aModel.createStream()).pipe(stream)
        }
        else if (stream.meta === 'channel2') {
            stream.pipe(bModel.createStream()).pipe(stream)
        }
    })

}).listen(8000)

aModel.on('update', function(data) {
    console.log('A updated with: ' + JSON.stringify(data))
})

bModel.on('update', function(data) {
    console.log('B updated with: ' + JSON.stringify(data))
})

// Client

var cModel = new Model
var dModel = new Model

server.on('listening', function() {

    //the client stream does not need to be piped inside the callback.
    //when creating a new connection, any messages are buffered.

    var stream = net.connect(8000)
    var mx = new MuxDemux
    mx.pipe(stream).pipe(mx)

    //use createStream - this creates a two way (duplex) stream
    //always use createStream when you pipe duplex style (a.pipe(b).pipe(a))
    var channel1 = mx.createStream('channel1')
    var channel2 = mx.createStream('channel2')

    channel1.pipe(cModel.createStream()).pipe(channel1)
    channel2.pipe(dModel.createStream()).pipe(channel2)

    //you only need mx.on('connection',...) on one side...
})

cModel.on('update', function(data) {
    console.log('C updated with: ' + JSON.stringify(data))
})

dModel.on('update', function(data) {
    console.log('D updated with: ' + JSON.stringify(data))
})

setTimeout(function() {
    aModel.set('bob', {a: 'valuea'})
}, 1000)

setTimeout(function() {
    bModel.set('bob', {b: 'valueb'})
}, 2000)

setTimeout(function() {
    cModel.set('bob', {c: 'valuec'})
}, 3000)

setTimeout(function() {
    dModel.set('bob', {d: 'valued'})
}, 4000)