HOUSTON (Reuters) - A federal judge on Tuesday threw out the 1983 conviction of former CIA (news - web sites) operative Edwin Wilson for selling tons of explosives to Libya, finding that prosecutors knowingly used false testimony and hid evidence that supported his defense. U.S. District Judge Lynn Hughes' opinion, written on Monday but made public on Tuesday, vacates Wilson's conviction for selling 20 tons of C-4 plastic explosives to the Libyan government of Col. Muammar Gaddafi (news - web sites). Wilson has been in prison since 1982, serving 52 years for three convictions including the arm sales to Libya....