NAJAF, Iraq (Reuters) - Pope Francis arrived at the home of Iraq’s top Shi’ite Muslim cleric in southern Iraq on Saturday for the first ever such meeting between the leaders of Roman Catholicism and Shi’ite Islam. Grand Ayatollah Ali al-Sistani was to greet Francis at his humble home in Najaf, the seat of the Iraqi Shi’ite clergy, on the second day of the pontiff’s historic tour of Iraq.