Prompt the user with a request to restart.

def prompt_restart_required(self):
        """Prompt the user with a request to restart."""
        restart_opts = self.restart_options
        changed_opts = self.changed_options
        options = [restart_opts[o] for o in changed_opts if o in restart_opts]

        if len(options) == 1:
            msg_start = _("Spyder needs to restart to change the following "
                          "setting:")
        else:
            msg_start = _("Spyder needs to restart to change the following "
                          "settings:")
        msg_end = _("Do you wish to restart now?")

        msg_options = u""
        for option in options:
            msg_options += u"<li>{0}</li>".format(option)

        msg_title = _("Information")
        msg = u"{0}<ul>{1}</ul><br>{2}".format(msg_start, msg_options, msg_end)
        answer = QMessageBox.information(self, msg_title, msg,
                                         QMessageBox.Yes | QMessageBox.No)
        if answer == QMessageBox.Yes:
            self.restart()