The nation's largest sandwich chain is said to be pressing down on the folks who make its bread and butter. Subway's been facing some struggles recently… and after franchise owners wrote an open letter asking the corporate team for support, the company responded by updating some policies in ways that, according to a new report, might seem like more of a breadknife in the back.Subway's seen a lot of drama this year. The recent launch of their Fresh Melts resulted in damage to some Subway store ow