A Phase II Multicenter, Randomized, Double-blind, Placebo-controlled, Dose-ranging, Parallel Group Study of the Safety and Efficacy of the Oral NeuroKinin-1 Receptor Antagonist, GW679769 in Combination with Ondansetron Hydrochloride and Dexamethasone for the Prevention of Chemotherapy-Induced Nausea and Vomiting in Cancer Subjects Receiving Moderately Emetogenic Chemotherapy