Prot# 9238IL/0048: Rndmzd, Dbl-Bld, Mltctr Study to Compare Effic & Tolrblty of Fulvestrant (FASLODEX?) vs Exemestane (AROMASIN?) in Postmenopausal Women w/ Hormone Receptor Positive Advanced Breast Cancer w/ Disease Progression after Prior Non-Steroidal