Previous adaptations lacked the bite that Roald Dahl put into his writing. Will this new version catch Dahl at his bleakest " and best?So Charlie, Willy Wonka, Violet Beauregarde, Mike Teavee, Veruca Salt and Augustus Gloop (the "great, big, greedy nincompoop") are about to arrive at London's Theatre Royal Drury Lane, in a musical version of Roald Dahl's bestselling childrens' novel Charlie and the Chocolate Factory.…