Carry #11858

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>

api/client/unpause.go

@@ -12,7 +12,7 @@ import (
 func (cli *DockerCli) CmdUnpause(args ...string) error {
 	cmd := cli.Subcmd("unpause", "CONTAINER [CONTAINER...]", "Unpause all processes within a container", true)
 	cmd.Require(flag.Min, 1)
-	cmd.ParseFlags(args, false)
+	cmd.ParseFlags(args, true)
 
 	var errNames []string
 	for _, name := range cmd.Args() {