LOS ANGELES, Aug. 8 - Like a live hand grenade brought home from a distant battlefield, the 34-year-old antiwar documentary "Winter Soldier" has been handled for decades as if it could explode at any moment. Now, the 95-minute film - which has circulated like 16-millimeter samizdat on college campuses for decades but has never been accessible to a wide audience - is about to get its first significant theatrical release in the United States, beginning on Friday at the Film Society of Lincoln Center. (Other bookings, including Chicago, Detroit, Hartford and Minneapolis, can be found at www.wintersoldierfilm.com.) Its distributors say...