CentOS has exception, so we keep installing with tasks

If for example a repository key is expired, this should not
block the whole processing, except when the package state is
"latest".

To achieve this, before installing package, we always try to
update apt cache in a separate step for which we tolerate
errors and in a second step we only install the package without
updating cache - unless the package state is latest.

The idea is when we want to install the latest package, it's a
problem if we can't update cache before, but when we just want
the package to be present, errors during apt update should are
not a problem.

Only debian was adjusted with this logic.

fixup for 203927d9

the filename was not OK (only used for Arch)

no more special mount directory for slapos stuff

update the slapos configuration

It seems some machines don't have the default 666 permission on
/dev/net/tun so we force it in the playbook.

Also add names to the tasks.

Since re6st is giving a /25 subnetwork to the machine and address 1 is
assigned to the host by re6st, it means we have only 125 addresses left
for tap interfaces.

See merge request !176

Cleanup unused and not working packages installations (socat)

See merge request nexedi/slapos.package!175

Fix random error "No space left on device".
For documentation, see
https://openbuildservice.org/help/manuals/obs-user-guide/cha.obs.build_job_constraints.html
For a case on OBS forum, see
https://forums.opensuse.org/t/obs-build-build-vm-line-427-echo-write-error-no-space-left-on-device/140717

Support MCA and fluent-bit plugin in separate packages.
Update command-line calls to the programs and files.

Update according to the .cfg file names in slapos repository.

Also update mca--static files:
- Update installation so that it does not install the plugin's files
anymore.
- Update dependencies.

ZC_BUILDOUT_VERSION variable cannot be defined in custom environments.

fluent-bit:
- Fix version number.
- Use home:oph.nxd OBS project.
mca--static:
- Update version.
- Use master branch in slapos repository.
- Use home:oph.nxd OBS project.

See 9bdb1695

by default, the bootstrap script will install newest buildout, but
starting with buildout 3.0.0, there is a problem of wheel like this:

ez_setup.py is deprecated and when using it setuptools will be pinned to 33.1.1 since it's the last version that supports setuptools self upgrade/installation, check https://github.com/pypa/setuptools/issues/581 for more info; use pip to install setuptools
Downloading https://pypi.io/packages/source/s/setuptools/setuptools-41.6.0.zip
Extracting in /tmp/tmpyglw2hza
Now working in /tmp/tmpyglw2hza/setuptools-41.6.0
Building a Setuptools egg in /root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs
warning: no files found matching '*.py' under directory 'tests'
warning: no previously-included files found matching 'pyproject.toml'
/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs/setuptools-41.6.0-py3.9.egg
Traceback (most recent call last):
  File "/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/bootstrap.py", line 199, in <module>
    ws.require(requirement)
  File "/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs/setuptools-41.6.0-py3.9.egg/pkg_resources/__init__.py", line 900, in require
  File "/root/slapos.package/obs/slapos/sn_1.8.3+1.0.290+1/slapos/build/opt/slapos/eggs/setuptools-41.6.0-py3.9.egg/pkg_resources/__init__.py", line 786, in resolve
pkg_resources.DistributionNotFound: The 'wheel' distribution was not found and is required by zc.buildout
Impossible to build SlapOS, exiting.
make: *** [Makefile:9: download_cache] Error 1