Reload the site from the database.

def reload_site(self):
        """Reload the site from the database."""
        rev = int(self.db.get('site:rev'))
        if rev != self.revision and self.db.exists('site:rev'):
            timeline = self.db.lrange('site:timeline', 0, -1)
            self._timeline = []
            for data in timeline:
                data = json.loads(data.decode('utf-8'))
                self._timeline.append(Post(data[0], self.config, data[1],
                                           data[2], data[3], self.messages,
                                           self._site.compilers[data[4]]))

            self._read_indexlist('posts')
            self._read_indexlist('all_posts')
            self._read_indexlist('pages')

            self.revision = rev
            self.logger.info("Site updated to revision {0}.".format(rev))
        elif rev == self.revision and self.db.exists('site:rev'):
            pass
        else:
            self.logger.warn("Site needs rescanning.")