The Internal Revenue Service on Wednesday extended until May 11 the deadline for filing federal income tax returns, a move that will give people affected by the floods nearly a month longer than usual to get their taxes done. The extension applies to all of Rhode Island, except Bristol County, which accounts for 5 percent of the state’s population, according to U.S. Census Bureau figures. The Rhode Island Division of Taxation will also extend its filing deadline to May 11 for all counties in Rhode Island without exception, state Tax Administrator David M. Sullivan said. “We will do the whole...