Implemented Socket buffering/flushing:

- Fires upon upgrade
- Fires when the transport is drained.

lib/socket.js

@@ -122,6 +122,7 @@ Socket.prototype.setTransport = function (transport) {
   this.transport = transport;
   this.transport.once('error', this.onError.bind(this));
   this.transport.on('packet', this.onPacket.bind(this));
+  this.transport.on('drain', this.flush.bind(this));
   this.transport.once('close', this.onClose.bind(this, 'transport close'));
 };
 
@@ -141,6 +142,7 @@ Socket.prototype.upgrade = function (transport) {
   // therefore we don't worry about the `open` event
   this.setTransport(transport);
   this.ping();
+  this.flush();
 };
 
 /**
@@ -196,6 +198,20 @@ Socket.prototype.sendPacket = function (type, data) {
   }
 };
 
+/**
+ * Attempts to flush the packets buffer.
+ *
+ * @api private
+ */
+
+Socket.prototype.flush = function () {
+  if ('close' != this.readyState && this.transport.writable) {
+    debug('flushing buffer to transport');
+    this.transport.send(this.writeBuffer);
+    this.writeBuffer = [];
+  }
+};
+
 /**
  * Closes the socket and underlying transport.
  *