President Obama welcomed four freely-elected African leaders to the White House Friday, saying democracy was “vital to a stable and prosperous Africa.” “Africa does not need strongmen; African needs strong institutions,” said the president, who met the leaders of Niger, Benin, Guinea and Cote D’Ivoire for talks on issues including trade, development, famine and ongoing partnerships with the U.S. , according to pool reports. The leaders -- Mahamadou Issoufou of Niger, Boni Yayi of Benin, Alpha Condé of Guinea and Alassane Ouattara of Cote D’Ivoire – were hailed by Obama as “effective models for the continent.” The leaders were chosen...