The final hearing at a United Nations war crimes tribunal was dramatically halted Wednesday when a former Bosnian Croat military chief claimed to have taken poison.Slobodan Praljak yelled, “I am not a war criminal!†and appeared to drink from a small bottle, seconds after judges reconfirmed his 20-year prison sentence for involvement in a campaign to drive Muslims out of a would-be Bosnian Croat ministate in Bosnia in the early 1990s. …Slobodan Praljak, 72, tilted back his head and took a gulp from a flask or glass as the judge read out the verdict.“I just drank poison,†he said....