changed flags so that the backend can work concurrently from multiple process; squished a few DBNotFoundErrors that orrur in some concurrent cases
changed flags so that the backend can work concurrently from multiple process; squished a few DBNotFoundErrors that orrur in some concurrent cases

git-svn-id: 60eb48102d1ca0c284ab3654bef916b01e1b221b@33 4f84a9ca-5c3e-0410-8a68-0bdf370325d5

nwebs/rdflib