By RICARDO CASTILLO     Who’s behind the letter President Andrés Manuel López Obrador (AMLO) sent to the king of Spain earlier this week demanding an apology for the atrocities against Mexican natives committed on orders of the king’s Borbón predecessors during 300 years of colonial rule from 1521 through 1821? The simple answer is, his wife, Beatriz Gutiérrez Müller. Did she really