Able to move alternate between comedy and melodrama, and portray everything from vixens to suffering mothers, the curvaceous yet full-boned, slender-nosed McClanahan has been on TV almost continuously since snagging the role of Vivian Harmon, best friend to "Maude", in 1972. Flirtatious and a bit ditzy as Vivian, McClanahan took out the "ditzy" but kept in the flirt more than a decade later when she created the role for which she is most recognized, that of Blanche Devereaux, self-proclaimed middle-aged sex goddess on "The Golden Girls" (NBC, 1985-92). With her Southern charm, girlish moves