Tributes are pouring in for Clive Barnes, the British-born New York critic who died yesterday after a quiet battle with cancer. “He knew his Shakespeare backward and forward, as well as his Sophocles, Ibsen, Chekhov and Congreve. He read the great novels, saw all of the great operas, loved classical music, was an expert on dance and knew one or two things about painting… At his best, Clive was a witty and vivid writer, never pompous and often downright impish.”