NEW YORK (AP) - Madonna isn't the person she once was - and that's the way she wants it. These days, the former Material Girl spends more time with her two children than she does performing. She collects art instead of boyfriends, and she's traded in her leather and lace undergarments for more demure outfits. In the August issue of Vogue magazine, Madonna is featured in a lengthy interview and a photo spread at the English country estate she shares with her children, 8-year-old Lourdes (Lola) and 4-year-old Rocco, and her director-husband, Guy Ritchie ("Lock, Stock and Two Smoking Barrels")....