From the skies above Riyadh to the rice terraces of Vietnam, and from barefoot islands in the Exumas to snow-draped chalets in the Alps, the month of May brings us yet more news from the world of luxury travel , with everything from a floating marina on a Four Seasons yacht, to a longevity retreat in Crete or a reimagined art deco palace in Shanghai. Read on for news from familiar names like Aman, Raffles, Etihad, and Disney…