code: public static String appendRemoteFileExtension(final String filepath, final String fileext) {
          return util.appendRemoteFileExtension(filepath, fileext);
      }
docs: @return a string with a file extension appended if it is not already on the file path
  provided.
  
  @param filepath the file path string
  @param fileext  the file extension, if it does not start with a "." one will be prepended
  first. If null, the unmodified filepath will be returned.