support transaction for postgre
support transaction for postgre

akira-cn/thinkjs,75team/thinkjs,maxzhang/thinkjs,snadn/thinkjs,thinkjs/thinkjs,akira-cn/thinkjs,Qihoo360/thinkjs,maxzhang/thinkjs,75team/thinkjs,75team/thinkjs,akira-cn/thinkjs,maxzhang/thinkjs