NAME:
    mwb_round
 PURPOSE: (one line)
    round a floating point number.
 DESCRIPTION:
    rounds a floating point number to the nearest whole number.
 CATEGORY:
    Mathematical
 CALLING SEQUENCE:
    mwb_round( x )
 INPUTS:
    x : The number to be rounded.
 OPTIONAL INPUT PARAMETERS:
    None.
 KEYWORD PARAMETERS:
    None.
 OUTPUTS:
    Function value: The rounded number.
 COMMON BLOCKS:
    None.
 SIDE EFFECTS:
    None.
 RESTRICTIONS:
    This is really an obsolete rountine, the system routine (round) is better
 PROCEDURE:
    Applies symmetric rounding to the given number.
 MODIFICATION HISTORY:
    Ported by Doug Loucks, Lowell Observatory, 1992 Sep, from the routine
    in pixwt.c written by Marc Buie.
   2017/04/25, MWB, renamed to mwb_round to avoid collision with system version