Only hide commands if the env variable is set.

Better formatting for usage template.
Group commands in usage to management/operation commands.
Remove the word Docker from the description of management commands.

Signed-off-by: Daniel Nephin <dnephin@docker.com>
Upstream-commit: a7c8bcac2ba60d6dd25a1157085d9245bed556ce
Component: engine

components/engine/cli/command/plugin/cmd_experimental.go

@@ -14,7 +14,7 @@ import (
 func NewPluginCommand(rootCmd *cobra.Command, dockerCli *command.DockerCli) {
 	cmd := &cobra.Command{
 		Use:   "plugin",
-		Short: "Manage Docker plugins",
+		Short: "Manage plugins",
 		Args:  cli.NoArgs,
 		Run: func(cmd *cobra.Command, args []string) {
 			fmt.Fprintf(dockerCli.Err(), "\n"+cmd.UsageString())