Print usage description for this program. Output is to standard out.

def usage(self):
    """Print usage description for this program. Output is to standard out."""
    print self.programName + " [options]",
    if self.maxArgs == -1 or self.maxArgs - self.minArgs > 1:
      print "[files..]"
    elif self.maxArgs - self.minArgs == 1:
      print "[file]"
    print

    print self.shortDescription

    print "Options:"
    for o in self.options:
      print "\t", ("-" + o.short + ", --" + o.long).ljust(15), ":",
      print o.description.replace("\t", "\\t").ljust(80)