“The Turning Door” is rare: an independent and ambitious animated feature based on an original story and script, with original songs. Nicholas Ashe Bateman (“An Almost Christmas Story”) directs, wrote the script, co-wrote the music and is one of the producers, and hopes that what he’s doing won’t be so unique in the future. Bateman, who, for some 15 years, worked in VFX and animation — a self-described “itinerant” worker who spent a lot of time coach surfing — sees a future where young