The SR of erp5-zope2 had the version of zc.buildout pinned to an
unpatched version that did not support build dependencies (
"setup-eggs").
This caused problems when trying to compile erp5-zope2 with recent
SlapOS in the test nodes, as it tries to use "setup_requires" instead,
which is not allowed:

```
Getting distribution for 'wstools'.
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
    ERROR: Command errored out with exit status 1:
     command: /srv/slapgrid/slappart19/t/eoa/shared/python2.7/3be205495452cf4067d1b6b952432c55/bin/python2.7 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-req-build-V_C9uf/setup.py'"'"'; __file__='"'"'/tmp/pip-req-build-V_C9uf/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-2KP9FV
         cwd: /tmp/pip-req-build-V_C9uf/
    Complete output (25 lines):
    DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
    WARNING: Url 'file:///dev/null/pytest-runner/' is ignored: it is neither a file nor a directory.
    ERROR: Could not find a version that satisfies the requirement pytest-runner (from versions: none)
    ERROR: No matching distribution found for pytest-runner
```

We remove these pins to use the latter version of buildout from
slapos.cfg.

In addition we adapt the erp5-zope2 buildout.cfg to buildout 3,
following the same steps as in 8c45efb1.

The version used for SOAPpy in erp5-zope2 was 0.12.0nxd001.
This is not a PEP 440-compliant version and thus compilation with the
newer buildout fails with:

``
Getting distribution for 'SOAPpy==0.12.0nxd001'.
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
  WARNING: Built wheel for SOAPpy is invalid: Metadata 1.2 mandates PEP 440 version, but '0.12.0nxd001' is not
ERROR: Failed to build one or more wheels
```

We upgrade the version to 0.12.22, which is the same that was done for
erp5 SR when buildout was upgraded.

The version of `cycler` in stack/slapos.cfg is overriding the version
specified in component/matplotlib/buildout.cfg.
This is a problem because the former does not take into account the
Python version, while the later does.
Thus, attempting to compile in Python 2 would give the following error:

```
Getting distribution for 'cycler==0.11.0'.
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop support for Python 2.7 in January 2021. More details about Python 2 support in pip can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support pip 21.0 will remove support for this functionality.
ERROR: Package 'cycler' requires a different Python: 2.7.18 not in '>=3.6'
While:
  Installing matplotlib.
  Base installation request: 'cycler', 'python-dateutil', 'numpy'
  Getting distribution for 'cycler==0.11.0'.
```

This removes `cycler` from `slapos.cfg`, so that it does not fail with
Python 2.

NEO does not currently work with Python 3.
Its dependency with Python 2 was removed in
nexedi/slapos@b3ac97ff
This causes erp5-zope2 to fail during installation with the following
message:

```python
Getting distribution for 'zope.testing==3.9.7'.
  error: subprocess-exited-with-error

  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [7 lines of output]
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "/tmp/pip-req-build-e3n8vnyw/setup.py", line 37
          except ImportError, e:
                            ^
      SyntaxError: invalid syntax
      [end of output]
```

Thus, we re-add the constraint in this commit.

  allOf implies that all (both) schemas should be valid, but
    additionalProperties false wont allow it, since it become multually
    invalid. (You can validate only one or None)

  Just use $ref to expand the list, it end up with the expected outcome
   reducing complexity.

  Note: kvm wasn't using additionalProperties false but it was changed
   because it makes it future proof, in case we set it (we should set).

Logs for the whole process shall be formatted in the same way, so define it
once in global section.

Long request lines result with truncated logs, which leads to impossibility to
debug cluster.

Maximize the log lines emitted by haproxy, and follow up this withing
accompanying rsyslogd.

Allow very long, but still much smaller, URI logging.

Compiling libuuid was failing with the following error:

```c
libuuid/src/gen_uuid.c: In function 'uuid_generate_time_generic':
libuuid/src/gen_uuid.c:536:33: error: initializer element is not constant
  THREAD_LOCAL int  cache_size = cs_min;
```

The error was previously detected, and a fix was provided in
52abdf6a , where the GCC minimum version
was increased to 8 (GCC version 8 supports using const-declared
variables as constant expressions in some cases).

Unfortunately, the solution did not work as the `min_version` field of
the `[gcc]` section was being overwritten by its value in
`component/defaults.cfg`.
This is because `util-linux` (where libuuid config is located) is a
transient dependence of `defaults.cfg` through `python3`.

Luckily, the error is already [patched upstream](https://github.com/util-linux/util-linux/commit/07e5c29d501c19e7af84fecb5915e0f9f94cb49f)
in version 2.40.1, so we can just upgrade the library to the latest
version instead (2.40.2), which we do here.

As part of the upgrade we disable the new tools added to the package, as
we do not use them: liblastlog2, pam-lastlog2 and exch.
Otherwise the compilation would fail with the following message:

```
configure: error: liblastlog2 selected, but required sqlite3 library not available
```

See merge request nexedi/slapos!1609

We can't use key of type dss anymore.

This is a fixup of aae4a7c0.

We can't generate key of type dsa anymore.

This is a fixup of aae4a7c0.

This reverts commit 5f4833c0.

It will solve a compilation error in libuuid