mainline: improved performance of ClientEngine
mainline: improved performance of ClientEngine

jmptrader/SuperSocket,fryderykhuang/SuperSocket,chucklu/SuperSocket,ZixiangBoy/SuperSocket,kerryjiang/SuperSocket,ZixiangBoy/SuperSocket,mdavid/SuperSocket,fryderykhuang/SuperSocket,chucklu/SuperSocket,ZixiangBoy/SuperSocket,memleaks/SuperSocket,jmptrader/SuperSocket,mdavid/SuperSocket,kerryjiang/SuperSocket,mdavid/SuperSocket,fryderykhuang/SuperSocket,chucklu/SuperSocket,jmptrader/SuperSocket