When Yahoo hired star Google executive Marissa Mayer to be its CEO in 2012 employees rejoiced. They put posters on the walls throughout Yahoo's California's headquarters. On them, there was Mayer's face and one word: HOPE. But just more than a year later on November 4, 2013 Mayer sat in front those same employees in a huge cafeteria on Yahoo's campus and took the beating of her life. Her hair w…