Merge pull request #1 from gweis/master

update rdflib-zodb to rdflib4
Update __init__.py

This should be a dev version for now as full compatibility and stability is not yet confirmed
don't use nose.collector as it finds the wrong files for python 3
gracefully close db and commit last open transaction
get rid of hard dependency on nose
use load_tests protocol to ensure we have a SkipTest exception
deactive testZGraphValue test as it fails with current rdflib 4 IOMemory backend
update tox.ini to fix python 3.2 test runs
use nose2 test runner because it supports load_tests protocol
added .gitignore