On Mac OS X the path returned by tempfile.mkdtemp is not the real path.
This makes the realtive_path test of easy_install.txt failing.
Calling os.path.realpath on the base directory fixed this testfailure for python 2.4 - 2.6.


git-svn-id: http://svn.zope.org/repos/main/zc.buildout/trunk@99818 62d5b8a3-27da-0310-9561-8e5933582275