BELEDWEYNE, Somalia — Islamist militants in Somalia have killed the widow of a Christian who was slain for his faith in December 2012, leaving the couple’s five children orphaned, sources said. Islamic extremist Al Shabaab rebels shot 42-year-old Fartun Omar to death April 13 in Buulodbarde, 12 miles from Beledweyne, Somalia, according to Abdi Aziz Suleiman of Radio Shebelle in…