Add comment to Distutil files about requiring 1.5.2 compatibility, as
    suggested by PEP 291.
diff --git a/Lib/distutils/errors.py b/Lib/distutils/errors.py
index 963d833..94e83fb 100644
--- a/Lib/distutils/errors.py
+++ b/Lib/distutils/errors.py
@@ -8,6 +8,8 @@
 This module is safe to use in "from ... import *" mode; it only exports
 symbols whose names start with "Distutils" and end with "Error"."""
 
+# This module should be kept compatible with Python 1.5.2.
+
 __revision__ = "$Id$"
 
 class DistutilsError (Exception):