Implement PEP 3121: new module initialization and finalization API.

Modules/errnomodule.c

@@ -53,17 +53,29 @@ Symbols that are not relevant to the underlying system are not defined.\n\
 To map error codes to error messages, use the function os.strerror(),\n\
 e.g. os.strerror(2) could return 'No such file or directory'.");
 
+static struct PyModuleDef errnomodule = {
+	PyModuleDef_HEAD_INIT,
+	"errno",
+	errno__doc__,
+	-1,
+	errno_methods,
+	NULL,
+	NULL,
+	NULL,
+	NULL
+};
+
 PyMODINIT_FUNC
-initerrno(void)
+PyInit_errno(void)
 {
 	PyObject *m, *d, *de;
-	m = Py_InitModule3("errno", errno_methods, errno__doc__);
+	m = PyModule_Create(&errnomodule);
 	if (m == NULL)
-		return;
+		return NULL;
 	d = PyModule_GetDict(m);
 	de = PyDict_New();
 	if (!d || !de || PyDict_SetItemString(d, "errorcode", de) < 0)
-		return;
+		return NULL;
 
 /* Macro so I don't have to edit each and every line below... */
 #define inscode(d, ds, de, name, code, comment) _inscode(d, de, name, code)
@@ -786,4 +798,5 @@ initerrno(void)
 #endif
 
 	Py_DECREF(de);
+	return m;
 }