使用EPOLL机制实现的WEB代理服务器，采用多线程和页面缓存技术。

用状态机来写一个socks5代理服务器，为了移植性和很多新手都在用windows，异步驱动我就只用select而没用epoll。-I have written a Proxy Socks5 server by using finite-state machine. Because of the so many people are studying under Windows, I just implement it by select not by epoll.