$231.9 million at Christie’s New York night sale of contemporary art. $190 million at Sotheby’s New York night sale of contemporary art. For summer, the art market action is centered in our on-line world, with “artnet Auctions.” Christie’s New York Imp & Mod sale confirms the art market recovery. Sotheby’s night sale of up to date art does $222.5 million. Giles Flint-Greenfield, a St James’ art vendor with a penchant for post-war British watercolours, is finding his world quite small. But when Ludo Abernathy, an old and far more profitable art dealer good friend, cuts him in on the mother…