Returns parser for given ``prog_name`` and ``subcommand``.

        :param prog_name: vcs main script name
        :param subcommand: command name

def get_parser(self, prog_name, subcommand):
        """
        Returns parser for given ``prog_name`` and ``subcommand``.

        :param prog_name: vcs main script name
        :param subcommand: command name
        """
        parser = OptionParser(
            prog=prog_name,
            usage=self.usage(subcommand),
            version=self.get_version(),
            option_list=sorted(self.get_option_list()))
        return parser