addHTML fixes for PHP 5.3

I found 2 bugs with the addHTML function. One when running under PHP 5.3 the default character encoding is ISO-8859-1 (This was changed to UTF-8 in PHP 5.4) which causes loadXML to hork because of it converts things like & nbsp ; to non-valid UTF-8 characters. The second is when you try to use an ampersand in the html you are trying to convert to docx.