You would hardly call it diminishing returns. The latest creative mani­festation of Alan Bennett’s reluctant hospitality to the woman known as Miss Shepherd, aka The Lady in the Van, began its run in UK cinemas as the second-most popular film at the box office. Miss Shepherd was the biggest thing after James Bond, something she herself might well have ­predicted.The story began in the late 1960s when the itinerant driver of a dilapidated Bedford van settled in Gloucester Crescent in London’s Camden, at the time an up-and-coming area. Over the next few years she’d shift along the pavement until Bennett found himself offering her a place in his driveway, where she stayed in odoriferous chaos for a decade and a half, until her death in 1989.Bennett wrote of this acc