By Julia Symmes Cobb BOGOTA (Reuters) – Colombian Marxist rebels released two captives on Tuesday and vowed to free a kidnapped army general by the weekend in a move that may lead to the resumption of suspended peace talks which aim to end five decades of war. President Juan Manuel Santos halted two-year-old negotiations in Havana after the Revolutionary Armed Forces of Colombia (FARC) seized five hostages, threatening to derail efforts to end a war that has killed more than 200,000 people since 1964. …