Fix undead containers
When a container has errors on removal, it gets flagged as dead.
If you `docker rm -f` a dead container the container is dereffed from
the daemon and doesn't show up on `docker ps` anymore... except that the
container JSON file may still be lingering around and becomes undead
when you restart the daemon.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>