change a small bit in the way valididy error messages get initialized

* parserInternals.c: change a small bit in the way valididy
  error messages get initialized
* python/TODO python/libxml.c python/libxml2-python-api.xml
  python/libxml2class.txt python/libxml_wrap.h python/types.c:
  added some memory debugging to track leaks at the libxml2 level
* python/tests/*.py: changed all tests to check for leaks,
  there is just one left in XPath extension registrations.
daniel

python/types.c

@@ -19,6 +19,17 @@ libxml_intWrap(int val) {
     return(ret);
 }
 
+PyObject *
+libxml_longWrap(long val) {
+    PyObject *ret;
+
+#ifdef DEBUG
+    printf("libxml_longWrap: val = %ld\n", val);
+#endif
+    ret = PyInt_FromLong(val);
+    return(ret);
+}
+
 PyObject *
 libxml_doubleWrap(double val) {
     PyObject *ret;