Reviewed in this essay: Young Adult, written by Diablo Cody and directed by Jason Reitman. Starring Charlize Theron, Patrick Wilson and Patton Oswalt. Running Time: 94 minutes. Playing in secondary run at select theatres. Amidst a winter season packed to the brim with flashy 3D eye candy (Tintin) and mushy-headed pulp (War Horse), it’s understandable…