MOSCOW (Reuters) – A scandal involving allegations of blackmail and threats against a top ballerina at the Bolshoi is unfolding just days after the artistic director of ballet at Russia’s most prestigious theatre was attacked, a Russian newspaper reported this week. Dancer Svetlana Lunkina has extended a leave of absence because she is afraid to return home from Canada as a result of threats targeting her and her film producer husband, Russian daily Izvestia reported in stories it ran on Monday and Tuesday. …