[feature] fix
[feature] fix tail space
[feature] helper API for send/recv
[feature] SOCKET_T
[feature] fix socket errno
[feature] replace socket transport layer by rex
[feature] stream transport
[feature] fix getseter of rex
[feature] fix tcp_listen/tcp_connect
[feature] remove strdup of unneed
[feature] get remote/local sockaddr when connection established
[feature] walk_fn for msgbuf_head
[feature] calculate the buf size by ubuf_len
Merge pull request #4 from proxyio/dev

replace the socket transport layer by rex socket