/* $DOC$
   $NAME$
      ft_Elapsed()
   $CATEGORY$
      Date/Time
   $ONELINER$
      Return elapsed time between two days and/or times
   $SYNTAX$
      ft_Elapsed([ <dStart> ], [ <dEnd> ], ;
                 <cTimeStart>, <cTimeEnd>) -> aTimedata
   $ARGUMENTS$
      <dStart> is any valid date in any date format. Defaults to Date().

      <dEnd> is any valid date in any date format. Defaults to Date().

      <cTimeStart> is a valid Time string of the format 'hh:mm:ss' where
      hh is hours in 24-hour format.

      <cTimeEnd> is a valid Time string of the format 'hh:mm:ss' where
      hh is hours in 24-hour format.
   $RETURNS$
      A two-dimensional array containing elapsed time data.
   $DESCRIPTION$
      ft_Elapsed() calculates the elapsed time between two Date/Time events.

      It returns an array which contains the following data:

      aRetVal[ 1, 1 ]  Integer Days      aRetVal[ 1, 2 ] Total Days    (nn.nnnn)
      aRetVal[ 2, 1 ]  Integer Hours     aRetVal[ 2, 2 ] Total Hours   (nn.nnnn)
      aRetVal[ 3, 1 ]  Integer Minutes   aRetVal[ 3, 2 ] Total Minutes (nn.nnnn)
      aRetVal[ 4, 1 ]  Integer Seconds   aRetVal[ 4, 2 ] Total Seconds (nn)
   $EXAMPLES$
      ft_Elapsed( 0d19901128, 0d19901130, "08:00:00", "12:10:30" )

      // will return:
      ? aRetVal[ 1, 1 ] // ->  2 ( Days )        aRetVal[ 1, 2 ] ->    2.1740  Days
      ? aRetVal[ 2, 1 ] // ->  4 ( Hours )       aRetVal[ 2, 2 ] ->   52.1750  Hours
      ? aRetVal[ 3, 1 ] // -> 10 ( Minutes )     aRetVal[ 3, 2 ] -> 3130.5000  Minutes
      ? aRetVal[ 4, 1 ] // -> 30 ( Seconds )     aRetVal[ 4, 2 ] -> 187830     Seconds
   $END$
 */