more work on RelaxNG streaming validation trying to improve the subset

* relaxng.c xmllint.c: more work on RelaxNG streaming validation
  trying to improve the subset compiled, and more testing.
* doc/downloads.html doc/xml.html doc/xmlmem.html: some updates on the
  documentation
* test/relaxng/tutor11_1_3.xml: fixes the DTD path
* result/relaxng/*.err: fix some of the outputs
Daniel
diff --git a/doc/xml.html b/doc/xml.html
index 9470892..2c45b25 100644
--- a/doc/xml.html
+++ b/doc/xml.html
@@ -580,7 +580,7 @@
     href="ftp://xmlsoft.org/">xmlsoft.org</a>, the source RPM will compile on
     any architecture supported by Red Hat.</li>
   <li><p><a href="mailto:igor@zlatkovic.com">Igor  Zlatkovic</a></p>
-     is now the maintainer of the Windows port, <a
+    is now the maintainer of the Windows port, <a
     href="http://www.zlatkovic.com/projects/libxml/index.html">he provides
     binaries</a>.</li>
   <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides
@@ -2460,9 +2460,14 @@
     memory when parsed). Validation will add a amount of memory required for
     maintaining the external Dtd state which should be linear with the
     complexity of the content model defined by the Dtd</li>
+  <li>If you need to work with fixed memory requirements or don't need the
+    full DOM tree then using the <a href="xmlreader.html">xmlReader
+    interface</a> is probably the best way to proceed, it still allows to
+    validate or operate on subset of the tree if needed.</li>
   <li>If you don't care about the advanced features of libxml like
-    validation, DOM, XPath or XPointer, but really need to work fixed memory
-    requirements, then the SAX interface should be used.</li>
+    validation, DOM, XPath or XPointer, don't use entities, need to work with
+    fixed memory requirements, and try to get the fastest parsing possible
+    then the SAX interface should be used, but it has known restrictions.</li>
 </ul>
 
 <p></p>