Prot# GS-US-196-0103: A Phase 2b, Randomized, Double-Blind, Placebo-Controlled Trial Comparing 24 or 48 Weeks of GS-9190, in Combination with Peginterferon Alpha 2a and Ribavirin, to 48 Weeks of Peginterferon Alpha 2a and Ribavirin for the Treatment of Ge