By Anthony Esposito and Alejandro Lifschitz BUENOS AIRES (Reuters) - President Cristina Fernandez's government sought on Monday to downplay a sobering defeat in Argentina's mid-term elections, asserting that its ability to govern has not been diminished even though voters shrank her majority in Congress and erased her chances of seeking a third term in 2015. The government's coalition took a beating in Sunday's elections, leaving her with only a slim majority in both legislative chambers. ...