applied patch from Stéphane Bidoul to fix some Python bindings

* python/libxml.c python/generator.py python/libxml.py
  python/libxml2-python-api.xml python/libxml2class.txt:
  applied patch from Stéphane Bidoul to fix some Python bindings
  initialization, then had to change the parserCleanup()
  to handle memory released there.
* xmlmemory.c: added more debugging comments.
Daniel
diff --git a/python/libxml.py b/python/libxml.py
index 0c3ba6c..5980974 100644
--- a/python/libxml.py
+++ b/python/libxml.py
@@ -618,6 +618,11 @@
             # assert f is _xmlTextReaderErrorFunc
             return arg
 
+#
+# The cleanup now goes though a wrappe in libxml.c
+#
+def cleanupParser():
+    libxml2mod.xmlPythonCleanupParser()
 
 # WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
 #