British director John Boorman had already made six movies before he got the chance to direct Exorcist II: The Heretic, the 1977 sequel to William Friedkin’s 1973 blockbuster about demonic possession, The Exorcist. Boorman was hardly a novice. He even had two stone-cold classics, Point Blank and Deliverance, to his name. But in making a movie about hope and goodness, in which Linda Blair’s former victim becomes a sort of psychic healer, Boorman …