Timothy Spall, a character actor best known as Peter Pettigrew in the Harry Potter movies and Winston Churchill in “The King’s Speech”, delivered a grunting, snorting, spitting, womanising warts-and-all performance in “Mr Turner” of the tortured Romantic landscape painter. The biopic traces the life of the iconoclastic genius who infused his depictions of threatening skies and stormy seas with reflections of his troubled inner life.