Make sure all workers look for their flagfile in the same spot.
Stop nova-manage from using /etc/nova/nova-manage.conf as its default
flagfile. This made made development awkward since everything but
nova-manage would use defaults for everything, but nova-manage would use
whatever config was in /etc/nova/nova-manage.conf which was likely put
there by a package of some sort.
This way, we can leave it to the packagers to set this default to
something else.