(In story dated May 22, corrects 2nd paragraph to say “information” instead of “secrets.” In 6th paragraph, updates to say statement was joint and adds name of official. Refers throughout to ‘Convention’ rather than ‘church’) By Rich McKay ATLANTA (Reuters) -For decades, complaints of sex abuse by pastors and staff in the largest U.S. Protestant denomination, the Southern Baptist Convention, were either ignored or covered up by top clergy, according to an internal report released on Sunday. The nearly 300-page report details how complaints were kept as “closely guarded information” within the …