Continues 11858 by:
- Making sure the exit code is always zero when we ask for help
- Making sure the exit code isn't zero when we print help on error cases
- Making sure both short and long usage go to the same stream (stdout vs stderr)
- Making sure all docker commands support --help
- Test that all cmds send --help to stdout, exit code 0, show full usage, no blank lines at end
- Test that all cmds (that support it) show short usage on bad arg to stderr, no blank line at end
- Test that all cmds complain about a bad option, no blank line at end
- Test that docker (w/o subcmd) does the same stuff mentioned above properly
Signed-off-by: Doug Davis <dug@us.ibm.com>
