YAOUNDE, Cameroon — Opposition leaders in Cameroon on Tuesday contested the official results of the Oct. 12 presidential election after the country’s top court declared that Paul Biya , the world’s oldest leader, had won re-election as protests continued across the country. Citizens began protesting in mid-October after opposition leader Issa Tchiroma Bakary claimed victory as the official results were still being tallied. Since then, security forces have clashed with angry protesters in many