Simple implementation of memcached protocol for both server and client side.
Not meant to replace memcached, but just sample code of network programming with muduo.

Server limits:
 - The memory management is not customized, just uses (tc)malloc.
 - It doesn't control the memory footprint
 - Unix domain socket is not supported
 - Only listen on one TCP port

Server goals:
 - Pass as many feature tests as possible
 - Prefer simplicity over performence

TODO:
 - incr/decr
 - UDP
 - Binary protocol
 - expiration
 - LRU