Add comment to Distutil files about requiring 1.5.2 compatibility, as

suggested by PEP 291.

Lib/distutils/command/build_ext.py

@@ -4,6 +4,8 @@ Implements the Distutils 'build_ext' command, for building extension
 modules (currently limited to C extensions, should accommodate C++
 extensions ASAP)."""
 
+# This module should be kept compatible with Python 1.5.2.
+
 __revision__ = "$Id$"
 
 import sys, os, string, re