Remember when the original Terminator — Herr Schwarzenegger in the role that made him a movie star — devastated an entire police station? Subsequent films in the series have upped the ante in terms of action and spectacle, but they have never topped the shock and awe of that comparatively simple sequence, when we realized what a formidable adversary this thing really was. Although “Terminator Salvation” recovers some of the ground ceded in the campy “Rise of the Machines,” this half-smart fourth installment has nothing to compete with that scene in “The Terminator,” not even when it features a 50-foot model