Filter containers by status.

A continuation of #7616.
Closes #7616.
Adds `docker ps --filter=status=(restarting|running|paused|exited)` option.

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Again the same but this time comma after "expressions".
It should be replaced with a period sign and "formats" should be capitalised, i.e.:

> .. expressions. Formats [..] will be ignored.