CANADA STOCKS-TSX tumbles after central bank comment, Ottawa shooting

* TSX tumbles 202.15 points, or 1.39 percent, at 14,345.56 * All 10 main index sectors fall * Energy shares slide with price of oil By John Tilak TORONTO, Oct 22 (Reuters) - Canada's main stock index dropped on Wednesday after a four-day winning streak as investors reacted nervously to monetary policy commentary from the Bank of Canada and news of shootings in Ottawa. A drop in the price of U.S. crude oil, which pulled energy shares lower, also weighed. The Bank of Canad