Implement to use X-Forwarded-* header

specifi a real request.

```
    X-Forwarded-For gives the address of the client which connected to the proxy
    X-Forwarded-Port gives the port the client connected to on the proxy (e.g. 80 or 443)
    X-Forwarded-Proto gives the protocol the client used to connect to the proxy (http or https)
    X-Forwarded-Host gives the content of the Host header the client sent to the proxy.
```
see: http://stackoverflow.com/questions/19084340/real-life-usage-of-the-x-forwarded-host-header