Bellefontaine Cemetery (4947 W. Florissant Avenue) is doing its part to make death less depressing. The more than 160-year-old north St. Louis cemetery has hosted concerts, cocktail parties and even booze-filled tours. Its newest addition, the Wildwood Valley Gardens, is another attempt at making Bellefontaine a less somber place — it's like a botanical garden in the midst of a cemetery.“Cemeteries are often seen as depressing.…