Added code submitted by Andreas Pakulat to provide node equality,

* python/libxml.c, python/libxml.py, python/tests/compareNodes.py,
  python/tests/Makefile.am:
  Added code submitted by Andreas Pakulat to provide node
  equality, inequality and hash functions, plus a single
  test program to check the functions (bugs 345779 + 345961).
diff --git a/python/libxml.py b/python/libxml.py
index 997e15f..f7c3129 100644
--- a/python/libxml.py
+++ b/python/libxml.py
@@ -232,6 +232,23 @@
             self._o = _obj;
             return
         self._o = None
+
+    def __eq__(self, other):
+        if other == None:
+	    return False
+        ret = libxml2mod.compareNodesEqual(self._o, other._o)
+	if ret == None:
+	    return False
+	return ret == True
+    def __ne__(self, other):
+        if other == None:
+	    return True
+        ret = libxml2mod.compareNodesEqual(self._o, other._o)
+	return not ret
+    def __hash__(self):
+    	ret = libxml2mod.nodeHash(self._o)
+	return ret
+
     def __str__(self):
         return self.serialize()
     def get_parent(self):