A Federal Reserve Bank survey found increasing optimism among Americans but also this jarring fact: Forty-seven percent of the people surveyed said they could not cover an emergency expense costing $400 without selling something or borrowing money. Other findings: • Sixty-five percent said their families are “doing OK” or “living comfortably” financially, up from 62 percent in 2013. • Forty-nine percent of part-time workers and 36 percent of all workers would like to work more hours…