By Abdoulaye Massalatchi NIAMEY (Reuters) - French special forces and Niger troops shot dead on Friday the last two Islamists involved in a twin attack on a military base and a French uranium mine in Niger claimed by the mastermind of January's mass hostage-taking in Algeria. Mokhtar Belmokhtar, a one-eyed veteran of al Qaeda's North African operations, said in a statement that his Mulathameen brigade organised Thursday's raids with the MUJWA militant group in retaliation for Niger's role in a French-led war on Islamists in Mali. ...