Jags move Justin Blackmon to the active roster

As expected, the Jacksonville Jaguars have officially added receiver Justin Blackmon to the active roster, a day before the team visits the St. Louis Rams. Blackmon, the fifth overall pick in 2012, recently returned to practice after a four-game suspension for violating the league’s substance-abuse program.  The Jaguars had been using a short-term roster exemption;…