Cannes is a bit of a holy place for film lovers. There are many so-called gods from the world of cinema at the festival. One is Palme d’Or-winning German director Wim Wenders. The three-time Oscar-nominated filmmaker’s new documentary brings a film crew inside the Vatican for the first time in history – for "Pope Francis: A Man of His Word". He speaks to Eve Jackson about what went on off camera, having carte blanche and what the pope would make of Cannes.