Reviewed by GREG KINGDirector: Gus Van SantStars: Joaquin Phoenix, Jonah Hill, Rooney Mara, Jack Black, Udo Kier, Kim Gordon, Beth Ditto, Mark Webber, Tony Greenhand, Carrie Brownstone.The late US cartoonist John Callahan is not a household name, and is largely unheard of outside of the United States, which makes this quirky and unconventional biopic a bit of a hard sell. Callahan died in 2010. Set in …