Pope urges peace in Mexico's poor, violent corners

By Philip Pullella and David Alire Garcia MEXICO CITY (Reuters) - From the U.S. border to the indigenous south, Pope Francis will visit some of the poorest and most violent corners of Mexico on his five-day trip and celebrates Mass on Saturday before an image of the country's patroness, the Virgin of Guadalupe. Chronic violence and corruption will be themes of his visit to the world's second most populous Roman Catholic country, and he will address the plight of migrants trying to reach the Unit