"As Oliver Stone completes the editing on his biographical film about Alexander the Great, a dramatic chapter in his own biography is coming to a close. The story of Mr. Stone's film chronicle of Fidel Castro, which began in 2002 with a three-day encounter that resulted in the sympathetic documentary 'Comandante,' concludes on Wednesday, when HBO broadcasts a more critical follow-up, 'Looking for Fidel,'" Elvis Mitchell reports.