listen to multiple servers, http and ssl, same socket io

simplify everything for simple single page facebook apps.
also fixed gzip pass the ci

```
var app=express();
var  server = require('http').createServer(app);
var io = sio.listen(server);
server.listen(80); 

var  serverssl = require('https').createServer(ssloptions,app);

io.addServer(serverssl);  //also listen to events of serverssl

serverssl.listen(443);
```