A Randomized Phase III Trial of Cisplatin plus Paclitaxel with and without NCI-Supplied Bevacizumab (NSC #704865; IND #113912) Versus the Non-Platinum Doublet; Topotecan Plus Paclitaxel; with and without NCI-Supplied Bevacizumab; in Stage IVB; Recurrent or Persistent Carcinoma of the Cervix