By Alexander Winning and Tim Cocks PRETORIA (Reuters) -The Ethiopian government and regional forces from Tigray agreed on Wednesday to cease hostilities, a dramatic diplomatic breakthrough two years into a war that has killed thousands, displaced millions and left hundreds of thousands facing famine. Just over a week after formal peace talks mediated by the African Union (AU) began in the South African capital Pretoria, delegates from both sides signed an agreement described by an AU official as a “permanent cessation of hostilities”. “The two parties in the Ethiopian conflict have formally ag…