Mash yolks with fork. Stir in mayonnaise, cayenne, shallots, celery, parsley and mustard until well blended. Set aside. In another bowl, mix crab, olive oil and chives. Refill whites, using about 1 tablespoon yolk mixture for each egg half. Top with the crab mixture. Chill to blend flavors. Garnish with bacon, if desired.