Make nan types sort to the end.
Make nan types sort to the end.

rdhyee/PyTables,FrancescAlted/PyTables,PyTables/PyTables,tp199911/PyTables,rdhyee/PyTables,dotsdl/PyTables,avalentino/PyTables,andreabedini/PyTables,mohamed-ali/PyTables,jack-pappas/PyTables,gdementen/PyTables,rabernat/PyTables,rabernat/PyTables,rdhyee/PyTables,mohamed-ali/PyTables,jennolsen84/PyTables,tp199911/PyTables,jennolsen84/PyTables,tp199911/PyTables,tp199911/PyTables,gdementen/PyTables,andreabedini/PyTables,jennolsen84/PyTables,dotsdl/PyTables,jack-pappas/PyTables,mohamed-ali/PyTables,PyTables/PyTables,joonro/PyTables,jack-pappas/PyTables,PyTables/PyTables,rdhyee/PyTables,dotsdl/PyTables,dotsdl/PyTables,avalentino/PyTables,jennolsen84/PyTables,joonro/PyTables,jack-pappas/PyTables,joonro/PyTables,rabernat/PyTables,gdementen/PyTables,rabernat/PyTables,FrancescAlted/PyTables,avalentino/PyTables,gdementen/PyTables,andreabedini/PyTables,andreabedini/PyTables,joonro/PyTables,mohamed-ali/PyTables,jack-pappas/PyTables,FrancescAlted/PyTables