fixed many-to-many example, which was utterly incorrect in many ways
fixed many-to-many example, which was utterly incorrect in many ways

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