a bit of cleanup small fix more work on the XmlTextReader tutorial a few

* xmllint.c: a bit of cleanup
* xmlreader.c: small fix
* doc/xmlreader.html: more work on the XmlTextReader tutorial
* python/libxml.py: a few fixes pointed out by Hannu Krosing
Daniel
diff --git a/python/libxml.py b/python/libxml.py
index a1b5a7b..6203e3d 100644
--- a/python/libxml.py
+++ b/python/libxml.py
@@ -302,11 +302,6 @@
         return libxml2mod.name(self._o)
     def get_type(self):
         return libxml2mod.type(self._o)
-    def get_doc(self):
-        ret = libxml2mod.doc(self._o)
-        if ret == None:
-            return None
-        return xmlDoc(_obj=ret)
     def free(self):
         libxml2mod.freeDoc(self._o)
 
@@ -356,7 +351,7 @@
     if name == "entity_decl":
         return xmlEntity(_obj=o)
     if name == "dtd":
-        return xmlAttr(_obj=o)
+        return xmlDtd(_obj=o)
     return xmlNode(_obj=o)
 
 def xpathObjectRet(o):