When you’re watching an episode of “Hawaii Five-0,” you’re guaranteed three things: gratuitous shots of Hawaii’s obscenely beautiful landscapes and shorelines, violent murders and adrenaline-packed action scenes.  The cop show’s admittedly rocky second season ended with the team briefly united before Steve traveled to Japan to finally meet the infamous “Shelburne,” and peril striking back Chin Ho and Kono back in Hawaii.  The third season starts on Sept. 24, so grab your coconut cocktails and prepare for the five spoilers you need to know...