In the summer, studios and exhibitors usually look to bread-and-butter blockbusters to boost business. This year, those sizzling titles include a new “Spider-Man” and Christopher Nolan’s “The Odyssey.” So, Hollywood wasn’t exactly obsessing over Focus Features’ springtime “Obsession,” a little indie released May 15 that was made for just $750,000 — less than a one-bedroom apartment in Manhattan. The film’s biggest name is Andy Richter. And its young and unknown writer-director, Curry Barker, is