It’s hardly the nicest stadium, but RFK Stadium holds a venerable place in Washington sports history. Open since 1962, when it was called District of Columbia Stadium, the venue has hosted two MLB franchises, the Washington Redskins during their glory years, the most successful MLS club ever, international soccer tournaments, concerts, and on and on. It even hosted Team America! Sunday’s final Nats home game, a 5-3 win over the Phillies, isn’t the last…