PHILIP PULLELLA and WAAKHE SIMON WUDU POPE Francis began a visit to South Sudan with an impassioned plea to its fractious leaders to turn their backs on the violence, ethnic hatred and corruption that have stopped the world's youngest country from achieving peace and prosperity. South Sudan broke away from Sudan to become independent in 2011 after decades of conflict, but civil war erupted in 2013. Despite a 2018 peace deal between the two main antagonists, violence and hunger still plague the country. Tens of thousands of people sang, drummed and ululated as the Roman Catholic leader arrived in the capital Juba…