In the 10 years since it debuted its first feature, The Secret of Kells, Cartoon Saloon has become a small but mighty force in the animation industry. The Kilkenny-based Irish studio, which employs only a couple hundred animators, is behind this year’s Oscar dark horse for animated feature, threatening the domination of Disney and Soul with the exquisite fantasy-adventure Wolfwalkers, the final film in its unofficial “Irish Folklore Trilogy.”