builtins now return success if supplied --help; use groff to build HTML man pages; reset mbstate if $'...' strings read an invalid multibyte sequence; read -t 0 now looks at other options (-n/-N/-d) and sets the terminal state appropriately

builtins/common.c

@@ -164,7 +164,7 @@ no_options (WORD_LIST *list)
       if (opt == GETOPT_HELP)
 	{
 	  builtin_help ();
-	  return (2);
+	  return (EX_HELPOPT);
 	}
       builtin_usage ();
       return (1);