By Jean Rimbach, The Record, Hackensack, N.J. Knight Ridder/Tribune Business News Dec. 31--Patrons belly up, and plunk down $9 a shot. But Atlantic City bartender George Kuhna isn't serving up the latest party drink. He's bubbling up scented oxygen and feeding gamblers, tourists, and conventioneers via a hose and a timer. Each hooks up to Lucite cylinders containing water in a choice of red, yellow, blue, or green and an array of fragrances to match. "It's pretty cool. I feel a lot better than I did when I started. I feel so fresh," says Maren Ferro, 23, of Franklin Lakes...