It was 1958 on Rush Street, or as one cab driver put it, “when Rush Street was still Rush Street.”There was Mister Kelly’s, The Happy Medium, Faces, The Trade Winds and Tony’s Cellar. A host of young comedians were emerging on the scene.There was the cool, scholarly Mort Sahl with his V-neck sweater, white shirt, opened at the collar and a daily newspaper in hand as he skewered President Eisenhower …