Papertown , a new documentary about the shutdown of an 115-year-old paper mill in an Appalachian town, is coming to screens, and it features a new song by Dave Matthews. You can hear some of it in the trailer out today. "The movie is stunning," Matthews says. "It's heartbreaking, but still so hopeful. It's full of hope, in spite of this class system where the power sits in the hands of far away people, which is so wrong." Here's the full synopsis of the film, which is directed by Jeremy Seifert and will have its will World Premiere at MountainFilm Festival in Colorado on May 22: When the 115-year-old paper mill that defined Canton, North Carolina unexpectedly announced it would shut down, it set off three turbulent months that would gut the town’s economy and shake its identity. This documentary moves with the community in real time, from the shock of the announcement to the mill’s final whistle.…