Update AUTHORS definition to be a comma-separated list of strings and/or update

the call to parse_long_options so that `AUTHORS, NULL' are the last parameters.

src/expr.c

@@ -188,7 +188,7 @@ main (int argc, char **argv)
   atexit (close_stdout);
 
   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
-		      AUTHORS, usage);
+		      usage, AUTHORS, NULL);
   /* The above handles --help and --version.
      Since there is no other invocation of getopt, handle `--' here.  */
   if (argc > 1 && STREQ (argv[1], "--"))