说明：  自己想写个手机版的飞鸽，所以翻译了一下它的协议，即使不打算自己做个飞鸽，学习下人家的协议还是好的。 加密总是最后才考虑的事，那段暂没翻译。
(Want to write their own version of a mobile ipmsg, so what it translated to an agreement, even if their not going to be a Feige, learning under the people' s agreement is still good. Encryption is always the last to consider the matter, did not translate that part temporarily.)