rc4 encrypt
support hot update service
Update README.md
reconstruct file tree
支持两种形式tunnel组织形式

1. front_door-tunnel_server <----- tunnel_client-back_door
2. front_door-tunnel_client -----> tunnel_server-back_door
Update README.md
Update README.md
support multi-tunnels
tunnel keepalive
Conn.Write would write all data
modify packet size
deal accept failed elegant
rewrite gotunel

去掉之前无用的特性，让gotunel回归单纯的tunnel
bugfix: 给基类注入一个代理，解决重载的问题
修改readme
修改readme
删除无用变量
bugfix: hub.dispatch hang
支持半双工
bugfix: get reader before dispatch other cmd except LINK_CREATE