Tucked behind the Westport Playhouse, walking into The Dressing Room, the restaurant started by Paul Newman, was much like walking into a wonderful old barn. Under the garland of lights strung up outside, and into a cozy nest of dark wood, old theatrical posters, a roaring fireplace and, above the bar, a television that alternated Newman’s movies with the ball game. Replacing the busy hum of conversation every other Friday were the dulcet and lovely tones of a female jazz…