MENA, Saudi Arabia, Dec 31 (Reuters) - More than 2.5 million Muslim haj pilgrims performed devil-stoning rites on Sunday, amid tight security to prevent overcrowding and protests following the execution of Saddam Hussein. The 5-day haj, marred by deadly stampedes in recent years, was overshadowed by the hanging on Saturday of the former Iraqi leader, a hero to some Sunni Arabs because of his anti-U.S. stance, but hated by many Shi'ites. "The number one Satan is America," said Iraqi pilgrim Suleiman Awadallah, who described himself as "a resistance fighter", after performing the stoning ritual. "The prayers of all Muslims when...