Update to wendelin.core 2, which reached its alpha state.

Even though it is wendelin.core 2, it continues to work by default in
wendelin.core 1 mode with providing the same stability guarantees as
before. This mode works with all ZODB4, ZODB4-wc2 and ZODB5. However
every Zope has its own private cache for ZBigFile data which wastes RAM,
prevents us to use as many Zopes as there are CPU cores, and potentially
leads to OOM issues where one Zope tend to allocate whole memory while
other Zopes cannot allocate even a single page. This mode, as well as
previous Wendelin.core 1, is also subject to data-corruption that can
happen on ZBigFile's BTree topology change:

nexedi/wendelin.core@8c32c9f6

WCFS mode - that is what wendelin.core 2 actually provides over
wendelin.core 1 - is currently opt-in. When used in "WCFS mode", all
Zopes share cache for ZBigFile data and there should be no data
corruption. This mode works with both ZODB4-wc2 and ZODB5, but not with
plain ZODB4. The way to opt-in into this mode for a software-release is
to set `erp5-defaults:wcfs-enable-default = true`, like SlapOS Master
currently does:

    # SlapOS Master needs to use Wendelin.core 2.
    # Wendelin.core 2 works with either ZODB4-wc2, or ZODB5, but not with ZODB4.
    # ERP5 does not currently work with ZODB5.
    # -> this leaves ZODB4-wc2 as the only choice.
    [ZODB]
    major = 4-wc2

    [erp5-defaults]
    wcfs-enable-default = true

Remove activate-WC2-preview.cfg as wendelin.core 2 is no longer draft
and there should be no need to use my personal repository and dirty
branch anymore.

SlapOS Master is going to use Wendelin.core 2.
Wendelin.core 2 works with either ZODB4-wc2, or ZODB5, but not with ZODB4(*).
ERP5 does not currently work with ZODB5.
-> this leaves ZODB4-wc2 as the only choice.

(*) see nexedi/ZODB@8e7eab33
for details.

/reviewed-by @tomo, @rafael
/reviewed-on nexedi/slapos!944

This profile will change in stack/erp5 and in erp5 haproxy will also play the
role of apache, but in slapos-master we will keep both apache and haproxy for
a while.

   This contains data for running tests on Upgrade

BT were moved into bt5/ subdirectory in
nexedi/erp5-doc@3996ae1f

   This library is required for a generic implementation of OAuth implementation of facebook login

  The version 0.4.0 uses an deprecated version of 
  GraphAPI which might not work anymore.

  Apply commits:
   stack.erp5: Drop unneeded executable permissions. (fe7ea950)
   stack.logrotate: Fix support for stopped processes.
   stack.erp5: Use an iterator to produce port numbers.
   software/erp5: if wendelin-core-zblk-fmt is not given, then use wendelin.core's default.
   software/erp5 & stack/erp5: Add a new parameter wendelin-core-zblk-fmt.

When originally in 0a446263 (ERP5 and Jupyter integrated together) I added
Jupyter support into ERP5 the parameter for whether to enable/disable it was
declared as boolean in JSON schema but processed as string in instance code,
this way preventing usage of real JSON's boolean.

Fix it.

(also fixing up software/slapos-master/ which copied the files for play in 87d13789)

/noticed-by @vpelletier (on nexedi/slapos!43)

  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

Those customization do not work anymore and it is preventing tests to run,
 so it should be reintroduced later in a way it works.

lab.nexedi.com is now our main domain for git hosting.
lab.nexedi.cn continues to work for backward-compatibility reasons.

/reviewed-by: TrustMe

slapos.core.git moved to lab.nexedi.cn and repository on git.erp5.org
made readonly. Update all referenced to old repository location:

    http://git.erp5.org/repos/slapos.core.git

->

    https://lab.nexedi.cn/nexedi/slapos.core.git

/reviewed-by trustme

New 'slapos-kill' from slapos.toolbox is used instead of 'killpidfromfile'
This is required for NEO which does not write any pid file.

Also put back certificates on software release url.

This is the only remote url which is going to be trusted outside of buildout.

Fetching list of keys over the network from non signed url has no sense.

All ERP5 profile is now in a single place.
Moreover, use slapos.cfg stack.

Also, stop referencing reference implicitly pulled parts.