It’s considered the jewel of the South’s social season, and on that subject, 400 Georgians can’t be wrong. AN ANNUAL BENEFIT FOR THE ATLANTA History Center, the Swan House Ball always takes place in April. Last year’s black-tie dinner-dance celebrated the 86th anniversary of the Italianate masterpiece, which was originally commissioned by a cotton broker and his wife, Edward and Emily Inman. The chairman, my buddy Aimee Chubb, called me to design the party and cook for it. I