"These are absolutely the dresses those bitches would wear!" giggles Linda St. John, proprietress of D.L. Cerney, pointing to a rack of cotton jacquard frocks lavished with cherries and sporting red-and-white checked bodices. The bitches in question are those maniacallyadare we say robotically?acontent housewives known collectively as the Stepford Wives, who returned to theaters last spring in their trademark saccharine dresses and sweetie-pie hats. The offerings at D.L. Cerney straddle with grace the sarcasm-sincerity line: Though they would look fine over ripped jeans, they also display a fetishistic attention to detailapearl buttons, tiny ventsato satisfy the starchiest suburban matron.