added "requires_quotes" step, subclasses of ANSIIdentifierPreparer can override
added "requires_quotes" step, subclasses of ANSIIdentifierPreparer can override

ThiefMaster/sqlalchemy,wujuguang/sqlalchemy,Akrog/sqlalchemy,wujuguang/sqlalchemy,wfxiang08/sqlalchemy,graingert/sqlalchemy,itkovian/sqlalchemy,ThiefMaster/sqlalchemy,robin900/sqlalchemy,davidjb/sqlalchemy,WinterNis/sqlalchemy,276361270/sqlalchemy,davidfraser/sqlalchemy,monetate/sqlalchemy,Cito/sqlalchemy,monetate/sqlalchemy,Cito/sqlalchemy,WinterNis/sqlalchemy,Cito/sqlalchemy,dstufft/sqlalchemy,bdupharm/sqlalchemy,pdufour/sqlalchemy,inspirehep/sqlalchemy,olemis/sqlalchemy,bootandy/sqlalchemy,dstufft/sqlalchemy,davidjb/sqlalchemy,alex/sqlalchemy,inspirehep/sqlalchemy,bootandy/sqlalchemy,Akrog/sqlalchemy,brianv0/sqlalchemy,brianv0/sqlalchemy,hsum/sqlalchemy,sandan/sqlalchemy,graingert/sqlalchemy,j5int/sqlalchemy,alex/sqlalchemy,halfcrazy/sqlalchemy,zzzeek/sqlalchemy,halfcrazy/sqlalchemy,olemis/sqlalchemy,itkovian/sqlalchemy,EvaSDK/sqlalchemy,bdupharm/sqlalchemy,sandan/sqlalchemy,j5int/sqlalchemy,davidfraser/sqlalchemy,epa/sqlalchemy,wfxiang08/sqlalchemy,elelianghh/sqlalchemy,epa/sqlalchemy,alex/sqlalchemy,sqlalchemy/sqlalchemy,hsum/sqlalchemy,elelianghh/sqlalchemy,pdufour/sqlalchemy,276361270/sqlalchemy,robin900/sqlalchemy,EvaSDK/sqlalchemy