RAMALLAH, West Bank (Reuters) – Two potential successors to 86-year-old Palestinian President Mahmoud Abbas were named on Monday to top posts in the Palestine Liberation Organization at a meeting boycotted by his Islamist rivals. Official Palestinian news agency WAFA said the PLO’s 141-member Central Council appointed Hussein Al-Sheikh, 61, an Abbas confidant who serves as key liaison with Israel and the United States, to the PLO’s Executive Committee. He is likely to replace the late Saeb Erekat as the committee’s secretary-general. The council, meeting for the first time in nearly four years…