Add .venv virtualenvs to gitignore
Enable  to test nested packages
runtests: Use nosetest paths set in $TESTERS if exists

If you don't want to use whichever `nosetests{,2,3}` runtests
automatically discovers in your path, run

    $ TESTERS="nosetests1 nosetests2" ./runtests

to change or limit which nosetests binary gets executed.
Try to fix problems with automatic albumart search tests