Configure DefaultUserAgent to not ignore comments in HTML documents.

(cherry picked from commit f556555)

Author: carlosame

src/io/sf/carte/doc/agent/net/DefaultUserAgent.java

@@ -131,6 +131,7 @@ public DOMDocument readURL(URL url) throws IOException, io.sf.carte.doc.Document
 		DocumentBuilder builder;
 		if (isHtml) {
 			builder = new HtmlDocumentBuilder(domImpl);
+			((HtmlDocumentBuilder) builder).setIgnoringComments(false);
 		} else {
 			XMLDocumentBuilder xmlbuilder = new XMLDocumentBuilder(domImpl);
 			xmlbuilder.setIgnoreElementContentWhitespace(true);