It's a bittersweet payday for hundreds of thousands of federal employees . Paychecks start going out today to 658,000 workers, with more to follow next week. As the government shutdown drags on , they will be lighter than usual — and the last ones until Congress reaches a funding deal. Even the guarantee of back pay is in question. "A lot of us are living paycheck to paycheck, like most Americans, but even more so now we have to be cognizant of where every penny is going," Mark Cochran, a