NEW YORK (Reuters) - As popularity contests go, vending machines may no longer be part of the "in" crowd in American high schools. At least, that is the hope of some legislators and health advocates. Last month, for example, the largest U.S. school district -- located in New York City -- decided to ban soft drinks, sweet snacks and candy from its vending machines. And more legislation, both state and local, is expected as legislators and educators battle a growing obesity epidemic. "Over the last two years, we've noticed a vast increase in the number of bills introduced that would...