allow overriding help name

command.go

@@ -157,7 +157,12 @@ func (c Command) startApp(ctx *Context) error {
 
 	// set the name and usage
 	app.Name = fmt.Sprintf("%s %s", ctx.App.Name, c.Name)
-	app.HelpName = fmt.Sprintf("%s %s", ctx.App.Name, c.Name)
+	if c.HelpName == "" {
+		app.HelpName = c.HelpName
+	} else {
+		app.HelpName = fmt.Sprintf("%s %s", ctx.App.Name, c.Name)
+	}
+
 	if c.Description != "" {
 		app.Usage = c.Description
 	} else {