Netflix has signed what is thought to be the world’s most expensive children’s content deal, buying rights to Roald Dahl works for a fee in the region of $1 billion, according to sources of The Hollywood Reporter. Netflix plans to make multiple animated series based on 16 of the celebrated author’s titles, including Charlie and the Great Glass Elevator, The BFG, The Twits, George’s Marvellous Medicine and The Enormous Crocodile. YouTube will be dropping the paywall for its premium original programming as of next year, shifting to its tried and tested ad-supported model, in a strategy the company has coined “Single Slate”. Sling TV has added nine Discovery networks and a few thousand VoD titles to its national and Spanish-language…