fixes involving when child object from list items is None - onetoone must pass, objectstore.testbackwardsmanipulations with postgres passes
fixes involving when child object from list items is None - onetoone must pass, objectstore.testbackwardsmanipulations with postgres passes

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