fixed __len__ and removed optimization interfaces (subjects,objects) for now
fixed __len__ and removed optimization interfaces (subjects,objects) for now



git-svn-id: 60eb48102d1ca0c284ab3654bef916b01e1b221b@470 4f84a9ca-5c3e-0410-8a68-0bdf370325d5

nwebs/rdflib