Don't let zpkgutils go on ZConfig cold turkey

releases/zpkg-support.pth

+# This allows the ZConfig checked out with Zope to be used by the zpkg
+# code invoked by setup.py.
+#
+# If zpkg ever requires a different version of ZConfig than Zope
+# provides as part of it's checkout, this file should be replaced by
+# an svn:external to the required version.
+#
+../lib/python