If present it will be used instead of /

It can be formatted with %(site-id)s in order to put site id there.

If added all country-code, email, state, city and company are required and are
later passed to certificate authority configuration.

Keep them simple, as section keys are local.

Make ssl-authentication really optional.

By configuring in JSON ssl-authentication to true for backend it will turn
listening apache to SSL based authorisation system.

SSL authorisation on such entry point is obligatory.

In order to follow typical ERP5 configuration SSL_CLIENT_S_DN_CN will be
passed as REMOTE_USER to Zope backend.

ERP5 CA is used to validate certificates.

This reverts commit 240cf0de.

Related problem was fixed by zc.buildout update.