[enh] language selection from query

    def parse_query(self):

        query_parts = self.query.split()

        modified = False

        if query_parts[0].startswith('!'):

        if query_parts[0].startswith(':'):

            lang = query_parts[0][1:]

            if lang in (x[0] for x in language_codes):

                self.lang = lang

                modified = True

        elif query_parts[0].startswith('!'):

            prefix = query_parts[0][1:].replace('_', ' ')

            if prefix in engine_shortcuts\

               and not engine_shortcuts[prefix] in self.blocked_engines: