We need to connect to the server each time we receive a request from broswer

And we need to replace the Connection from "Keep-alive" to "Close" when forwarding the request. Otherwise, the server will keep a counter called "max" in "Keep-Alive" and tears down the connection soon.  see also
http://tools.ietf.org/id/draft-thomson-hybi-http-timeout-01.html#rfc.section.2.2


I have done the client part. I send back response with Connection = Close, and close the socket afterwards.
I put close(fd) after a new accept() to avoid blocking...  (by this, I can wait for the browser to close connection first)