PHILIP PULLELLA and WAAKHE SIMON WUDU POPE Francis urged the people of South Sudan to resist the "venom of hatred" so they could achieve the peace and prosperity that have eluded them through years of bloody ethnic conflicts. In his last public engagement before flying home, Francis presided at an open-air Mass on the grounds of a mausoleum for South Sudan's liberation hero John Garang, who died in 2005. The Vatican said 100,000 people attended the Mass. The 86-year-old pope wove his homily around the themes that have dominated his trip to the world's newest nation -- reconciliation and mutual forgiveness…