specifying HTML_PARSE_NOWARNING and HTML_PARSE_NOERROR options do not
prevent parser from displaying some warnings.

* unwanted output sample:
-----
element form: validity error : ID search already defined
element select: validity error : ID rhpath already defined
element map: validity error : ID introLinks already defined
element a: validity error : ID technologies already defined
element a: validity error : ID news already defined
element a: validity error : ID search already defined
-----

* code sample:
-----
  htmlParserCtxtPtr ctxt = NULL;
  htmlDocPtr doc = NULL;

  ctxt = htmlCreateMemoryParserCtxt (buffer, strlen (buffer));
  if (ctxt != NULL)
  {  
    htmlCtxtUseOptions (ctxt, HTML_PARSE_NOWARNING | HTML_PARSE_NOERROR);    
    htmlParseDocument (ctxt);  

    doc = ctxt->myDoc;  
    if (doc != NULL && doc->children != NULL)  
    {    
      html_parser_parse (doc->children);  
    }  

    htmlFreeParserCtxt (ctxt);
}
-----