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>

cli/command/volume/cmd.go

@@ -13,7 +13,7 @@ import (
 func NewVolumeCommand(dockerCli *command.DockerCli) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "volume COMMAND",
-		Short: "Manage Docker volumes",
+		Short: "Manage volumes",
 		Long:  volumeDescription,
 		Args:  cli.NoArgs,
 		Run: func(cmd *cobra.Command, args []string) {