clean_cache 协程清理重写
prepare for persistent storage of group info
初始化数据库
avoid "database schama has changed"

reconnect before excute or reconnect on throw "database schama has changed"
revert avoid "database schama has changed"

use shared cache!
group list info insert into database
move buddy mgr to seperated lib
刷新群qq号~
as the buddy_mgr progress, more operation move to coroutine
groups and buddies now all stored in sqlite database.

the groups and buddies info all stored in database.
makding buddies member readonly
fix qqnum 无抓取 bug
fix a bug cause silent igonre!
fix  null value fetched but no indicator!
等待 group_message 被处理
some rewrite
update avboost
delay 逻辑修正
无需管理员, 新人第一次发言就可以获取到! 哈哈
some logical fix!