/* $DOC$
   $NAME$
      ft_ElTime()
   $CATEGORY$
      Date/Time
   $ONELINER$
      Compute difference between times in hours, minutes, seconds.
   $SYNTAX$
      ft_ElTime( <cTime1>, <cTime2> ) -> cDiff
   $ARGUMENTS$
      <cTime1, cTime2>  character strings representing times in
         hh:mm:ss format.
   $RETURNS$
      <cDiff>  character string representing time difference in
         hh:mm:ss format.
   $DESCRIPTION$
      Return the absolute difference between two times in hh:mm:ss format
      in character hours, minutes and seconds (hh:mm:ss).
   $EXAMPLES$
      ? ft_ElTime( "22:40:12", "23:55:17" )  // 01:15:05
      ? ft_ElTime( "23:55:17", "22:40:12" )  // 01:15:05
   $SEEALSO$
      ft_ElapMin(), ft_Mil2Min(), ft_Min2Mil()
   $END$
 */