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.

This implements the idea of the patch from
https://bugs.launchpad.net/zope2/+bug/143352
but also honours the trusted-proxy setting.

The unimportant events have changed names.

Fixes LP #1095343.

Fixes LP #1095343.

Fixes LP #1094144.

Fixes LP #1094144.

Fixes LP #1094221.

Fixes LP #1094221.