Sri Lanka’s president on Monday appointed a general accused of grave human rights abuses in the final stages of its long civil war as the country’s new army chief – a move the United Nations says may affect contributions to UN peacekeeping missions.The new commander, Major General Shavendra Silva, who was also promoted to the rank of lieutenant general, was in charge of the 58th Division which encircled the final stronghold of the Tamil Tiger rebels in the last stages of the civil war in 2009…