“A Hard Straight” follows three California parolees as they try to put their lives back together. That's no mean feat. “It's easy to get in and hard to get out,” sighs Aaron “Shep” Shepard, who's continually running afoul of his parole officers in San Francisco's Tenderloin. For Regina Allen, the problem is substance abuse. And ex-gang member Richard “Smiley” Martinez has a girlfriend and young son, and can make a decent living as a tattoo artist. But gang ties are hard to break.