fix #194

Also fixes rendering of this HTML:
<table width=100px border=1>
<tr><td>aaa<td style="display:none">bbb<td>ccc

and this HTML:
<style>p{display:table-cell}</style>
<p>aaa</p><!----><p>bbb</p>

and improves rendering of this HTML:
<style>
p{display:table-cell}
span{white-space:pre}
</style>
<span>
<p>aaa</p>  <p>bbb</p>