While not a household name like Matt Groening, animation director David Silverman was arguably one of the most instrumental behind-the-scenes craftsmen of the perennial sitcom family, “The Simpsons” (Fox, 1989- ). Silverman was a struggling animator in the 1980s – before the boom in feature film and prime-time animation – and was on the verge of quitting when he took a chance on a series of short bumpers about a dysfunctional cartoon family on “The Tracey Ullman Show” (Fox, 1987-1990). A key player in laying the ground rules for transforming Groening’s two-dimensional drawings into characters