testing strategy:
 - use an external method with a transaction manager which sleeps
  for 20 seconds during tpc_vote and tpc_commit
 - commit such a transaction
 - stop zope
 - check the stop happens after the tpc_commit

https://mariadb.com/kb/en/enabling-core-dumps/

For now this still have to be enabled with a config like this in a .conf
file in srv/telegraf/extra-config/  :

    [[inputs.execd]]
      name_override = "slapos"
      # this needs sudo when using can not access supervisor socket, like when being installed in root slapos
      command = ["/usr/bin/sudo", "$SOFTWARE_DIR/go.work/bin/telegraf-input-slapos", "-config", "/path/to/slapos.conf"]

/path/to/slapos.conf would contain something like this:

    [[inputs.slapos]]
      ## Folder where partitions are located
      instance_root = "/srv/slapgrid/"

      ## filepath.Glob pattern to look for recursive instances
      recursive_instance_glob_pattern = "*/srv/runner/inst*/"

      ## Path of supervisor socket, relative to instance root
      socket_name = "sv.sock"

This version has a new sql input, that can be used to get metrics from sql
queries.

This reverts commit 31eaaec1.

This slows down business template by a factor of two and it seems we
don't need it. I'm experimenting with hacks in ppml.py but maybe just
creating the Unpickler with encoding='utf-8' in
product/ERP5Type/XMLExportImport/__init__.py:267 is enough ?

at this point they all fail after long timeouts, because neo does not
support py3 yet

Not sure why it was OK on python2 and not sure if this has to be done
or the promise code needs to cast the results of getConfig()

Otherwise it fails with the following exception because of non-ASCII characters
(`[A-Z&é@{]{3,7})`) (see unconvert()) below):

  => erp5_core/PathTemplateItem/portal_preferences/default_site_preference.xml
     File "zodbpickle-2.0.0-py3.7-linux-x86_64.egg/zodbpickle/pickle_3.py", line 844, in load
        dispatch[key[0]](self)
     File "zodbpickle-2.0.0-py3.7-linux-x86_64.egg/zodbpickle/pickle_3.py", line 1035, in load_short_binstring
        self.append(self.decode_string(data))
     File "zodbpickle-2.0.0-py3.7-linux-x86_64.egg/zodbpickle/pickle_3.py", line 989, in decode_string
        return value.decode(self.encoding, self.errors)
  UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 19: ordinal not in range(128)

This reverts commit 6c399134.

This change the format or the (mostly) unused frontend parameter to
support requesting more than one frontend and also enable the request of
a frontend by default, so that requesting a frontend separately is no
longer needed.

The `frontend` parameter now also supports requesting frontends for
specific paths on the ERP5 backend, the example below requests a
frontend serving directly a web site, with the necessary rewrite rules:

```js
{
  "frontend": {
    "default": {
      "internal-path": "/erp5/web_site_module/renderjs_runner/"
    }
  }
}
```

The example below requests a default frontend to the erp5 root, to
access the ZMI or erp5_xhtml_style interface and two web sites:

```js
{
  "frontend": {
    "default": {},
    "erp5js": {
      "internal-path": "/erp5/web_site_module/renderjs_runner/"
    },
    "crm": {
      "internal-path": "/erp5/web_site_module/erp5_officejs_support_request_ui/"
    }
  }
}
```

The example below has an explicit definition of the zope families using
`zope-partition-dict` parameter, because there is more than one zope
family, no frontend is requested by default:

```js
{
  "zope-partition-dict": {
    "backoffice": {
      "family": "backoffice"
    },
    "web": {
      "family": "web"
    },
    "activities": {
      "family": "activities"
    }
  }
}
```

Continuing this example, to have frontends for backoffice and web
families, the frontend request can specify the families, like it is
demonstrated in the example below. In this example, we don't specify an
entry for "activities" family, so no frontend will be requested for
this family.

```js
{
  "frontend": {
    "backoffice": {
      "zope-family": "backoffice"
    },
    "web": {
      "zope-family": "web",
      "internal-path": "/erp5/web_site_module/web_site/"
    }
  }
  "zope-partition-dict": {
    "backoffice": {
      "family": "backoffice"
    },
    "web": {
      "family": "web"
    },
    "activities": {
      "family": "activities"
    }
  }
}
```

See merge request nexedi/slapos!1486

Use runTestSuite interface to launch tests that request instances
on actual SlapOS cloud.

As described in https://github.com/msgpack/msgpack-python#major-breaking-changes-in-msgpack-10
raw is False by default for unpacker so we receive strings, not bytes

See merge request nexedi/slapos!1490

ZODB4 does not support python3

These must be installed through dependencies, but we explicitly need
scripts from supervisor because this is used by slapos-core tests

on python3 we use lzma directly

This software only use nodejs for a simple build step, it should be OK
to use any version.

Hello up there.

I've noticed that wendelin.core tests became failing to build and
automatically disabled some time ago. Not good. I've tried to fix build
failures. Please see individual patches for details.

/cc @levin.zimmermann
/reviewed-by @jerome
/reviewed-on nexedi/slapos!1492