By Denny Dyroff, Entertainment Editor, The Times Gov’t Mule When Gov’t Mule headlines a show on November 1 at The Met (858 North Broad Street, Philadelphia, http://themetphilly.com), the band’s fans will be in for a special treat. Every year, Gov’t Mule plays a special show at the end of October — Mule-O-Ween. Gov’t Mule — Warren Haynes – guitar, lead vocals (1994–present),...