If you grew up watching “Sesame Street,” you know Jim Henson’s characters well. The late puppeteer brought Kermit and Ernie and so many others to life before he went on to create “The Muppet Show” and “Fraggle Rock.” But as his son Brian Henson tells us, the legendary artist and performer didn’t set out to just entertain kids. He wanted his work to reach a wider audience. Which is why Henson poured his creativity into directing the 1986 film “Labyrinth.” “Star Wars” creator George Lucas produced, and David Bowie starred in the musical fantasy. Despite all the talent involved, “Labyrinth” bombed at the box office. But, today, it’s a cult classic. Here’s why.