Zend_View_Helper_HeadTitle does not implement prefix and postfix values in toString

Should be something like:

    public function toString($indent = null)
    {
        $indent = (null !== $indent)
                ? $this->getWhitespace($indent)
                : $this->getIndent();

        $items = array();
        foreach ($this as $item) {
            $items[] = $this->_escape($item);
        }

        $separator = $this->_escape($this->getSeparator());
        $output = '';
        if ($prefix = $this->getPrefix()) {
            $output .= $prefix;
        }
        $output .= implode($separator, $items);
        if ($postfix = $this->getPostfix()) {
            $output .= $postfix;
        }
        return $indent . '' . $output. '';
    }