Movies for Grownups Weekend Update: Dec. 6

Just one bona fide grownup movie opening this weekend, but it’s a doozey: The return of the Coen Brothers and their favorite cameo star, John Goodman.  The New Stuff:     Inside Llewyn Davis Filmmaker brothers Joel and Ethan Coen made their name as outrageous geniuses (Raising Arizona; O, Brother Where Art Thou?; No Country for Old Men), but this time they’ve dampened their quirky tendencies-and created what may be their most balanced movie ever. Inside Llewyn Davis is a …