NAME:
  mpcdcvt
 PURPOSE:
  Convert to and from Minor Planet Center packed designation format.
 DESCRIPTION:
  A Minor Planet Center designation starts with J, or K.  A "normal"
    desination starts with a number.  Either type can have a leading '('
    that indicates it is a secondary designation.  This leading character is
    not stripped off.  If it does not start with J, K, or a numeral, the
    name is left alone.
  This routine converts the input into the other form.
 CATEGORY:
  Astrometry
 CALLING SEQUENCE:
  outstr = mpcdcvt(instr)
 INPUTS:
  instr - String (or array) to be converted.
 OPTIONAL INPUT PARAMETERS:

 KEYWORD INPUT PARAMETERS:

 OUTPUTS:
  outstr - String (or array) of converted strings.
 KEYWORD OUTPUT PARAMETERS:

 COMMON BLOCKS:

 SIDE EFFECTS:

 RESTRICTIONS:

 PROCEDURE:

 MODIFICATION HISTORY:
  2000/05/03, Written by Marc W. Buie, Lowell Observatory
  2002/03/22, MWB, eliminated a minor nuisance message during conversion.
  2002/05/28, MWB, fixed a formatting bug for numbered asteroids.
  2003/08/12, MWB, fixed a bug when converting 2000-2029 designations to
                     packed format.