Add bash completion for "docker rm -f" and complete on all containers instead of just stopped containers when "-f" is specified

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Merge pull request #6693 from tianon/bash-complete-force-rm

Add bash completion for "docker rm -f" and complete on all containers instead of just stopped containers when "-f" is specified