JOSIANE KOUAGHEU  ONE protester was killed in Cameroon as police and gendarmes put down protests against the veteran President Paul Biya, the country's main opposition party said, while accusing security forces of laying siege to their leader's home. Police and gendarmes fired tear gas and water cannon to break up protests in the commercial hub of Douala, calling for an end to Biya's near 40-year rule, Reuters witnesses said. Maurice Kamto The rally was called by 87-year-old Biya's closest rival, Maurice Kamto, of the Cameroon Renaissance Movement party, who hopes to spark a popular revolt as seen in other African…