DAR ES SALAAM (Reuters) - The suspected architect of Rwanda's 1994 genocide begins a fourth week of testimony on Monday defying accusers in the biggest trial to date over the central African nation's 100 days of slaughter. Prosecutors at the UN's Tanzania-based International Criminal Tribunal for Rwanda (ICTR) say former army colonel Theoneste Bagosora, now 64, was in charge as troops and machete-wielding militiamen butchered some 800,000 people. But in lengthy comments from the stand, Bagosora has accused rebel-turned-president Paul Kagame of triggering the bloodshed, blamed the chief of UN peacekeepers for the murder of Rwanda's prime minister and even...