By Mark Lamport-Stokes LOUISVILLE Kentucky (Reuters) - Two victories by Bubba Watson in the first four months of this year, including a second triumph at the Masters, highlighted a sizzling start to the 2013-14 PGA Tour by the long-hitting American. Though Watson has since failed to maintain that red-hot momentum, missing the cut at the U.S. Open and also at last month's British Open, he was in confident mood on Tuesday about his prospects for this week's PGA Championship. My six and five-iron are going to get a lot of work this week." Asked if he was at all disappointed with how his PGA Tour form had tailed off over the past few months, Watson replied: "No, I'm not disappointed. More...