Non-Persistent HTTP RPC Support

Hi, we have a microservice system based on rpcplus, we now need to export most of our services to the browser, since rpc uses a persistent connection and connects with "CONNECT" method, i refactored some part of the code and added a "server" that handles single open-close request responses. It has so small differences from other "servers"

With this change anyone will be able to use rpcplus as their web api server.