function convertEntities(_str) {
    return _str.replace(ENTITY_MATCH, function(fullMatch, innerMatch) {
        var outChar;
        if(innerMatch.charAt(0) === '#') {
            // cannot use String.fromCodePoint in IE
            outChar = fromCodePoint(
                innerMatch.charAt(1) === 'x' ?
                    parseInt(innerMatch.substr(2), 16) :
                    parseInt(innerMatch.substr(1), 10)
            );
        } else outChar = entityToUnicode[innerMatch];

        // as in regular HTML, if we didn't decode the entity just
        // leave the raw text in place.
        return outChar || fullMatch;
    });
}
Strip string of tags

@param {string} _str : input string
@param {object} opts :
- len {number} max length of output string
- allowedTags {array} list of pseudo-html tags to NOT strip
@return {string}