Things keep changing at Dove Valley.  The “Denver Post” reports receiver Javon Walker has joined the Raiders, a week after the Broncos let him go.  Today, the Broncos hope to sign cornerback Champ Bailey’s brother Boss.  Boss Bailey is a free-agent linebacker who played with the Lions last season.  He’s in town for a visit today and tomorrow.  San Diego safety Marlin McCree also stops by, as he weighs offers from Denver and Buffalo.