'Print a long help message to stdout and exit(0).
Occurrences of "%s" in are replaced by self.progname.'

def help(self, dummy):

    help = (self.doc + '\n')
    if (help.find('%s') > 0):
        help = help.replace('%s', self.progname)
    self.stdout.write(help)
    self.exit(0)
