This changes were squashed into a single commit and it includes:

    - install slapos_configurator by default
    - Allow define ssl authentication for a certain zope family
    - Allow define custom zope path per zope family

  Those changes are originally written by Alain Takoudjou and rewrited by Rafael Monnerat

  The local changes are not yet generic enough to be shared among stack, so
  Introduce local changes here better

Implemented using libuserhosts. Only provided to zope processes so far, may be
extended in the future with each process seeing different sets of aliases,
with potentially different resolutions.

Move haproxy httpchk configuration per-listen as zope's webdav returns 401
on (at least) GET / . TCP-level checks are still active, which should be
sufficient.
Also, change zope_family_address_list check to getitem as it's more natural
than concatenating.
Also, stop using apache.zope.backend recipe to add support for per-port
scheme so automatic ERP5Site creation knows which URL is really HTTP.
Also, stop using certificate_authority recipe and call openssl directly
when generating self-signed cert for https/webdavs support.
Also, rework balancer parameters a bit (still undocumented).
Also, make instance-balancer always publish ipv6 value (empty when no ipv6
available), so instance-erp5 always succeeds.

Not perfect yet, as some strings end in configuration files for example
and need escape mechanisms aware of individual configuration file syntaxes.

Also, generate password randomly if not provided instead of using an
hardcoded value.
Publish them as they can be generated internally.