NAME:
  windstr
 PURPOSE:   (one line only)
  Convert a wind direction angle to a string name (or back).
 DESCRIPTION:
 CATEGORY:
  Miscellaneous
 CALLING SEQUENCE:
  wname = windstr(wdir)
 INPUTS:
  wdir - Wind direction in degrees, scalar or vector
            if numbers are provided, these are converted to strings
            if strings are provided, they are converted to integers
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  return value is the name of the wind direction (string) or the numeric
    value depending in the input.
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  Note that the names are coarser than numbers. If you start with numbers,
    convert to names and then back to numbers you probably won't get the same
    answer.
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Lowell Observatory, 2005/03/26
  2008/02/03, MWB, changed to allow reverse transformation.