Avoid restarting standalone when embedded instance parameters change.

Without this we sometimes hit the socket path length limit when testing
ERP5 inside Theia inside erp5testnode.

wait a first time that ERP5 have finished processing activities for
initial site creation and tolerate that during this time zopes might
reply with error code

In ubuntu 21.04 (libc6 2.33-0ubuntu5) or current debian testing
(libc6 2.32-5) no longer use open to open /etc/hosts, but what appears
as "openat" in strace output - but can not be replaced by defining an
openat function.

This uses https://github.com/figiel/hosts which uses another approach
of replacing getaddrinfo, gethostbyname* and inet_aton.

Users have been updated a bit, because there are some small differences:
 - the /etc/hosts replacement file is defined by HOSTS_FILE environment
   variable, not HOSTS
 - the library name is libuserhosts.so, not userhosts.so

Other notable differences, for which we did not need code change are:
 - the new library also try to load a file when HOSTS_FILE is not set
 - the new library still use original /etc/hosts file
 - the new library supports aliases to hostnames, not only ip addresses

on debian 11, old software does not compile with an error like:

    ERROR: ld.so: object '/srv/slapgrid/slappart47/t/dcm/i/0/tmp/shared/userhosts/e880bfd75804e2ec50f297b173a4ae9a__compile__/userhosts-1d3b463e7856db6e674a06258c0840206e6a7b72-1d3b463e7856db6e674a06258c0840206e6a7b72/userhosts' from LD_PRELOAD cannot be preloaded (cannot dynamically load position-independent executable): ignored.

the fixes have been backported to a new 1.0.167.5 tag

This test is installing an old version of ERP5 that did not satisfy all
the software checks. We don't want to check the old version and we check
the new version in software/erp5/test so no need to check here.

instance-repman-slave-input-schema.json: Move parameters that are used for cluster to
`repman-cluster-dict`
cluster-config.toml: autorejoin and autoseed parameters are moved to cluster config file

multiarch() is being removed from slapos.recipe.build , it was not
needed because we can achieve this with buildout conditional sections as
we did here.

Test defining setUp and tearDown needs to call methods from super class,
where snapshots are collected.

with a backported patch to fix compilation with gcc 10

On Debian 10 the test was successful because it could use the system
python (usr/bin/python). In Debian 11 the system python isn't available
anymore, therefore it fails. To ensure the Fluentd program can successfully
execute the "python custom_read_bme280.py" command, the script passes
the same python binary to the Fluentd config file with which the test
is called (sys.executable).

@romain reports that Popen(close_fds=True) is slow on py2. Let's semantically
backport from py3 how to close only actually opened file descriptors instead of
whole 3..`ulimit -n` range.

Attached test benchmark shows the following results with `ulimit -n`=65K:

Before this patch:

    $ ./bin/python2.7 ~/x.py
    close_fds=False:
    0.001251 s/call
    0.001337 s/call
    0.001486 s/call

    close_fds=True:
    0.017973 s/call
    0.018152 s/call
    0.018204 s/call

After the patch:

    $ ./bin/python2.7 ~/x.py
    close_fds=False:
    0.001391 s/call
    0.001416 s/call
    0.001570 s/call

    close_fds=True:
    0.001469 s/call
    0.001479 s/call
    0.001491 s/call

i.e. ~12x speedup.

References on this subject are in the patch itself.

The test benchmark is below:

---- 8< ----
import timeit
from subprocess import check_call

def f():
    check_call(['true'], close_fds=False)
def g():
    check_call(['true'], close_fds=True)

N=3
n=100
print 'close_fds=False:'
for i in range(N):
    print '%.6f s/call' % (timeit.timeit(f, number=n) / n)
print
print 'close_fds=True:'
for i in range(N):
    print '%.6f s/call' % (timeit.timeit(g, number=n) / n)

/helped-by @jm

This version fixes build for debian >= 11

On debian 11, linking against libnsl link against several system
libraries and the check software check fail.

these are dependencies of postfix

  - access log
    - log rotation
    - username is logged (expected failure in WSGI)
  - event log
    - log rotation
  - long requests log (expected failure in WSGI)
    - log rotation
  - activity processing
  - deadlock debugger