Joe Gibbs and Charley Casserly, who successfully collaborated at Washington during Gibbs’ first coaching tenure, meet this weekend as rivals, with Casserly currently serving as the VP/General Manager of the Houston Texans. Both still have one thing in common, however: their respective teams are off to disappointing starts this season, and eye this weekend’s contest as a chance to put themselves back on the right track. This week, Redskins quarterback Mark Brunell found himself back…