Theodore Roosevelt was famous for gunboat diplomacy. But Donald Trump's ambassador to Italy has found a rather more luxurious way to win friends: love boat diplomacy. Billionaire entertainment mogul Tilman Fertitta, 69, is wooing foreign officials from the deck of his $450 million mega yacht, the Boardwalk, as he cruises around Italy on a two-and-a-half-month 'Coastal Diplomatic Tour.' The 383ft vessel boasts two helipads, two swimming pools, four hot tubs, a fully equipped spa, scuba room, putting green and cinema, with business tycoons and sports personalities rubbing shoulders with government officials at lavish receptions. Fertitta, the world's 312th-richest person according...