Refactor and add IETF-07 protocol version support.

- Add initial IETF-07 (HyBi-07) protocol version support. This version
  still uses base64 encoding since the API for binary support is not
  yet finalized.

- Move socket send and recieve functions into the WebSocketServer
  class instead of having the sub-class do this. This simplifies
  sub-classes somewhat. The send_frame routine now returns the number
  of frames that were unable to be sent. If this value is non-zero
  then the sub-class should call again when the socket is ready until
  the pending frames count is 0.

- Do traffic reporting in the main class instead.

- When the client is HyBi style (i.e. IETF-07) then use the
  sub-protocol header to select whether to do base64 encoding or
  simply send the frame data raw (binary). Update include/websock.js
  to send a 'base64' protocol selector. Once the API support binary,
  then the client will need to detect this and set the protocol to
  'binary'.

tests/echo.html

@@ -92,7 +92,7 @@
             }
             uri = scheme + host + ":" + port;
             message("connecting to " + uri);
-            ws = new WebSocket(uri);
+            ws = new WebSocket(uri, "base64");
 
             ws.onmessage = function(e) {
                 //console.log(">> WebSockets.onmessage");