POPAYAN (Reuters) - Colombians rejoiced at the killing of top FARC rebel leader Alfonso Cano and hoped the biggest blow yet against Latin America's longest insurgency could herald an end to nearly five decades of war. In a triumph for President Juan Manuel Santos' hardline security policy, officials said forces bombed a FARC jungle hide-out in the mountainous southwestern Cauca region. Troops then rappelled down from helicopters to search the area, killing the widely hated Marxist rebel boss, his girlfriend and several other rebels in a gun battle on Friday.