add coro, http_download wrapper re-write as coro
timer rewrite
add resolver
update asio style
coyield rename to _yield

yabami _yield is better than coyield. yield conflict with boost, so
_yield is choieen
some kind of resolver fix
add base64 decoder
base64 解码ok
move operator() to pop3.cpp
timedcall: use more friendly name timer
final fix
add boost::async_connect that takes query("","") as endpoint
connector.hpp 沉默是金子
add ifdef guard
proxy
use boost::async_avconnect
add ifdef to enable SSL
some connector fix
fix segfault
some update