Backport some Python 2.5 compatibility work
Backport some Python 2.5 compatibility work

--HG--
branch : setuptools-0.6
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/branches/setuptools-0.6%4051932

pypa/setuptools,pypa/setuptools,pypa/setuptools