Give 'em an inch and they'll take a mile. Consumers on Facebook (NASDAQ: FB ) are excoriating fast-food sandwich shop Subway for selling "footlong" subs that come up short. About an inch short.When a picture appeared on Subway's fan page showing one of its sandwiches alongside a ruler indicating it was just 11 inches long, not 12, it quickly went viral and soon others were posting their own pictu