[Bug 1090071] `docker start` doesn't fail on started container

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1090071

Matthew Heon  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |MODIFIED

--- Comment #4 from Matthew Heon  ---
Pull request for man pages submitted to upstream. Not sure if this is
necessarily appropriate for in-command help documentation, which is usually
kept more brief.

https://github.com/dotcloud/docker/pull/6182