Randomized phase III trial to compare the effectiveness of paclitaxel with that of doxorubicin in treating patients who have advanced AIDS-related Kaposi's sarcoma. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. It is not yet known whether paclitaxel is more effective than doxorubicin in treating patients with advanced AIDS-related Kaposi's sarcoma