Dallas Cowboys trade for Green Bay Packers LB Jayrone Elliott, cut Cedric Thornton

FRISCO, Texas — The Dallas Cowboys were busy Sunday trying to improve their defense.

The team acquired outside linebacker Jayrone Elliott in a trade with the Green Bay Packers for a conditional seventh-round pick in 2018 and were awarded defensive tackle Brian Price off waivers from the Packers. And, perhaps most surprisingly, they cut defensive tackle Cedric Thornton, their biggest…