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)
Actually, that's wrong. It's the opposite. A comma is needed before `temp?` because commas are used to wrap parenthetical statements, which is what this is. But don't sweat it. This is on my list of things I need to go back and edit.

Decent explanation here: http://www.quickanddirtytips.com/education/grammar/dashes-parentheses-and-commas?page=2