President George W Bush's personal chef has been humiliated by a team of French practical jokers who tempted him with a job offer to desert his employer and go to work for President Jacques Chirac.The stunt, which is threatening to spiral into a diplomatic incident, happened when Walter Scheib visited Paris in his capacity as president of the Chefs des Chefs d'Etat, a club for those who cook for the world's heads of state.On Wednesday evening he was due to attend a party at the Elysee Palace given by the French leader's wife, Bernadette. That afternoon a French television company...