(Reuters) - Saudi Arabia and Russia spearheaded a deal on Friday in which OPEC and its allies committed to some of the deepest oil output cuts this decade aiming to avert oversupply and support prices.The group of more than 20 producers agreed to an extra 500,000 barrels per day (bpd) in cuts for the first quarter of 2020, taking the total to 1.7 million bpd, or 1.7% of global demand.Brent oil rose 2% to more than $64 a barrel after Saudi Energy Minister Prince Abdulaziz bin Salman said..