Date.parse fails on IETF style dates with negative time-zone offset

Date.parse fails on IETF style dates that have a negative timezone offset.
Such dates are common in rfc822 mail messages, so this prevents us from using
the Date class reliably ...

Example:
-------
import java.util.*;
public class x {
        public static void main(String argv[]) {
                Date d = new Date("Thu, 5 Sep 1996 17:44:11 -0700");
                System.out.println(d.toString());
        }
}