Unix sockets and ip binding

Changing HttpServer to suport Unix sockets and bind with different ip. Adding two more examples, one with ip binding and the other is a client/server using Unix socket.
I don't know the implications of changing HttpHandler to be type instead of be immutable.
If there's anything wrong, please let me know, i'm trying to using this webserver to build some services with Nginx in from of it, using unix files to proxy pass the requests.