OXNARD, Calif. — Forget the pads and the scorecard for a second. Tuesday's joint practice between the Cowboys and the Rams wasn't really about winning a period, no matter how many training-camp Twitter accounts tried to hand out a trophy for it. It was about finding out who you are before the lights come on. Dallas got exactly what it came for out in Southern California — a heavyweight sparring session against a Rams roster that, on paper, might be the best they see all summe