Fix Issue#115: Possibility to bypass class_name check in queryset.
Fix Issue#115: Possibility to bypass class_name check in queryset.

MakerReduxCorp/mongoengine,hmarr/mongoengine,khallaghi/mongoengine,losintikfos/mongoengine,yarneo/mongoengine,Davidrjx/mongoengine,MongoEngine/mongoengine,gmacon/mongoengine,WingGao/mongoengine,blaggacao/mongoengine,gavincabbage/mongoengine,depop/mongoengine-stripped,RussellLuo/mongoengine,MRigal/mongoengine,touilleMan/mongoengine,Multiposting/mongoengine,DavidBord/mongoengine,starsirius/mongoengine,eli-b/mongoengine,elephanter/mongoengine,ContextLogic/mongoengine,KarimAllah/mongoengine,muhammad-ammar/mongoengine,Davidrjx/mongoengine,conversocial/mongoengine,iandd0824/mongoengine,ProgressivePlanning/mongoengine,larsbutler/mongoengine,aszwemin/mongoengine,ConsumerPhysics/mongoengine,noirbizarre/mongoengine,ms5/mongoengine,MakerReduxCorp/mongoengine,cogniteev/mongoengine,ContextLogic/mongoengine,9nix00/mongoengine,nicolascine/mongoengine,cogniteev/mongoengine,prijindal/mongoengine,closeio/mongoengine,newvem/mongoengine,sourcelair/mongoengine,colinhowe/mongoengine,reallistic/mongoengine,jimmyshen/mongoengine,Catstyle/mongoengine,nathanial/mongoengine