The Pirates and back up catcher Chris Stewart have agreed to a three million two year deal with a club option for a third.  Stewart will earn 1.35 million in  2016, 1.4 million in 2017.  The club option  for 2018 is 1.5 million with a team  buy out of 200-thousand.  Stewart’s deal comes less than a week after the Pirates  avoided arbitration with starting catcher Francisco Cervelli.  Cervelli will  make 3.5 million in 2016.