Prepare Acquisition 4.0a1.

CHANGES.txt

 Changelog
 =========
 
-4.0 (unreleased)
-----------------
+4.0a1 (2011-12-13)
+------------------
 
 - Raise `RuntimeError: Recursion detected in acquisition wrapper` if an object
   with a `__parent__` pointer points to a wrapper that in turn points to the

setup.py

@@ -17,7 +17,7 @@ import os
 from setuptools import setup, find_packages, Extension
 
 setup(name='Acquisition',
-      version = '4.0dev',
+      version = '4.0a1',
       url='http://pypi.python.org/pypi/Acquisition',
       license='ZPL 2.1',
       description="Acquisition is a mechanism that allows objects to obtain "