By Seamus Duff A new BBC adaptation of an Agatha Christie classic has been panned by one of today’s top rated authors. His Dark Materials writer Philip Pullman \- whose own fantasy book series has been adapted into a hit series by the BBC in collaboration with HBO – has lashed out at the lavish production of Murder Is Easy. The period drama stars David Jonsson as detective Luke Fitzwilliam who is alerted to a crime by Penelope Wilton’s anxious character Miss Pinkerton – before a serial killer is found to be at large in the quiet town of Wychwood under Ashe. The all-star cast includes The Rings…