WASHINGTON — Senior defense officials say Pentagon chief Leon Panetta is removing the military’s ban on women serving in combat, opening hundreds of thousands of front-line positions and potentially elite commando jobs after more than a decade at war. The groundbreaking move recommended by the Joint Chiefs of Staff overturns a 1994 rule prohibiting women from being assigned to smaller ground combat units. Panetta’s decision gives the military services until January 2016 to seek special exceptions if they believe any positions must remain closed to women. A senior military official says the services will develop plans for allowing women to …