Fashionistas, socials and even a convicted media baron came to Le Cirque Tuesday for the wedding of Arnold Scaasi and Parker Ladd, who have been together 50 years. Guests including Martha Stewart, Tory Burch, Mica Ertegun, Alfred and Judy Taubman, Arlene Dahl, Marc Rosen, Iris Love and First Deputy Mayor Patricia E. Harris were given postcards depicting the couple a half-century ago in Capri. But the real eye-turner was Conrad Black, who’s due back in federal prison in September to complete his sentence for fraud. Bill Cunningham and Patrick McMullan photographed the cocktail party and a smaller dinner for 20.