NAME:
  mkrundate
 PURPOSE:   (one line only)
  Create a run date string given a Julian Date.
 DESCRIPTION:
 CATEGORY:
  Utility
 CALLING SEQUENCE:
  rundate = mkrundate(jd)
 INPUTS:
  jd - Julian Date (scalar)
 OPTIONAL INPUT PARAMETERS:
  DATE - Flag, if set will format the output as a valid mysql date string
           (ex: 2012-03-12).  The default is a rundate string which is
           a 6-digit string (ex: 120312).
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  return value is a 6-digit string that is the run date for the input JD
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  2008/06/22, Written by Marc W. Buie, Southwest Research Institute
  2012/03/07, MWB, added DATE keyword