openFile: have Haddock comments mention openBinaryFile
-- * 'isDoesNotExistError' if the file does not exist; or
--
-- * 'isPermissionError' if the user does not have permission to open the file.
-
+--
+-- Note: if you will be working with files containing binary data, you'll want to
+-- be using 'openBinaryFile'.
openFile :: FilePath -> IOMode -> IO Handle
openFile fp im =
catch