ARDMORE, Pennsylvania (Reuters) - Rory McIlroy is one of the few top golfers pleased to see the heavy rain falling at Merion, the site for this week's U.S. Open. While many of his opponents have bemoaned the arrival of the showers and the slower greens and softer fairways, McIlroy's mood perked up when he heard the forecast for more torrential weather. Rather, the Northern Irishman thinks the ...