Dali was there of course and Audrey Hepburn showed up with her head trapped inside a Magritte birdcage. Never has there been a dinner party quite like the “Diner de Têtes Surrealiste” that took place at the suburban Parisian mansion of Baron Guy de Rothschild and his ‘hostess with the mostess’, Marie-Helene de Rothschild. Only the crème…