Matching line separators when decoding JSON aknowledgement data

Socket.IO client is not parsing aknowledgement JSON data correctly, because is not matching new line and line separator characters. When using these characters in a JSON packet the acknowledgement function is called with no arguments.

Testing code:

```javascript
var io = require('socket.io').listen(8888);

io.sockets.on('connection', function (socket) {
  socket.on('ack', function(fn){
      fn({ "a": "\u2028" });
  });
});

var io = require('socket.io-client');
var socket = io.connect("http://localhost:8888");
socket.on('connect', function(){
    socket.emit('ack', function(data){
        console.log(data); // Here data is lost
    });
});
```