function unescapeHtml(subject) {
    var subjectString = coerceToString(subject);
    return characters.reduce(reduceUnescapedString, subjectString);
  }
Unescapes HTML special characters from <code>&amp;lt; &amp;gt; &amp;amp; &amp;quot; &amp;#x27; &amp;#x60;</code>
to corresponding <code>< > & ' " `</code> in <code>subject</code>.

@function unescapeHtml
@static
@since 1.0.0
@memberOf Escape
@param  {string} [subject=''] The string to unescape.
@return {string}              Returns the unescaped string.
@example
v.unescapeHtml('&lt;p&gt;wonderful world&lt;/p&gt;');
// => '<p>wonderful world</p>'