TORONTO (Reuters) - Comedian Tommy Chong has spent almost three decades wringing laughs from cigar-sized joints and smoke-filled vans but now a nine-month jail term has turned him serious and revitalized his flagging career. Promoting his documentary "a/k/a Tommy Chong" at the Toronto International Film Festival, he hopes the film will expose what he says is the U.S. government's heavy-handed dealing with marijuana offenders in the post-September 11 era. "The United States is under martial law, it's under dictatorship," the 67-year-old father of four said in an interview. The film chronicles the Canadian-born comedian's 2003 arrest and imprisonment for selling...