[server] modularize the socket management.
[server] modularize the socket management.

The standard tells to use TCP/IP socket for HTTP. But why not to use
UDP/IP socket or other protocol to transfert HTTP message ?
This commit is a first step to allow the change of protocol.

mchalain/libhttpserver,mchalain/libhttpserver,ouistiti-project/libhttpserver,ouistiti-project/libhttpserver