code: function (str) {
              return str.replace(getUnEscapeReg(), function (m, n) {
                  return htmlEntities[m] || String.fromCharCode(+n);
              });
          }
docs: un-escape html to string.
  only unescape
  &amp; &lt; &gt; &#x60; &#x2F; &quot; &#x27; &#\d{1,5}
  @param str {string} html2text
  @member KISSY
  @return {String} un-escaped html