MARKETING MANEUVERS: This summer will find National Frozen & Refrigerated Foods Association, Harrisburg, Pa., promoting refrigerated and frozen foods on the CBS "Super Screen" in New York City's Times Square. NFRA will sponsor three 10-second commercials each hour, 18 hours a day during the months of June, July, August and September. Respectively, the ads will promote June dairy month, ice cream and novelties, refrigerated and frozen food convenience for back-to-school schedules and an educational program connecting refrigerated and frozen foods to good nutrition. . . .Kellogg Co . said it will promote itsGardenburgerveggie burger with a "mobile culinary experience." A traveling GardenFresh Cafe will tour Seattle, Portland, Ore., Austin, Texas, and Denver to sample product and use local chefs for live demos. . . .TheBoston Marketbrand is now airborne.American Airlines, Fort Worth, Texas, said it would begin offering brandedBoston Marketsandwich and salad options on select flights. H.J. Heinz, Pittsburgh, has retail packaged product rights.