- Products.BTreeFolder2:  2.13.5.

WSGI begin / end interaction fixes

Backporting WSGIPublisher interaction fixes.

Wrap in try-finally.

Cherry-pick c73dfcd1 from master.

Make it analogous to the ZServer publisher.

Cherry-pick 41594f6d from master.

- DateTime: 2.12.8
- zLOG: 2.11.1.

Note repos which need (but don't yet have) such release branches.

- Products.ExternalMethod -> 2.13.1

- Products.MailHost -> 2.13.2

- Products.StandardCacheManagers -> 2.13.1

Prevent leaked connections when broken 'EndRequestEvent' subscribers raise

Fixes #16 on the 2.13 branch.

Update setuptools and zc.buildout to currently-installable versions.

- setuptools 12.0.5
- zc.buildout 2.3.0

If base Python has  installed, mandate creating a virtualenv
without setuptools, and using it to bootstrap Zope.

See: http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/

Trying to fix https://bugs.launchpad.net/zope2/+bug/1387225 changed format of self.args in superclass

Trying to fix bug https://bugs.launchpad.net/zope2/+bug/1387138. zope is trying to import a symbol which is not at the expected place anymore.