fix(Help Subcommand): fixes a bug where the help subcommand couldn't be overriden

Closes #787

Author: kbknapp

src/app/parser.rs

@@ -240,7 +240,7 @@ impl<'a, 'b> Parser<'a, 'b>
         debug!("Parser::add_subcommand: Is help...");
         if subcmd.p.meta.name == "help" {
             sdebugln!("Yes");
-            self.settings.set(AppSettings::NeedsSubcommandHelp);
+            self.settings.unset(AppSettings::NeedsSubcommandHelp);
         } else {
             sdebugln!("No");
         }