otherwise system library is used

When running tasks, shell is invoked like:

   $THEIA_SHELL -c "command with arguments that\ can\ contain\ spaces"

The version from theia images does not support running from a plugin
installed in a read only folder, this newest version seem to work.

Also set the required java.home setting

So that gitlens extension (which can be installed per-workspace) knows
how to open files from lab.nexedi.com in browser

so that we can easily use python version 2 or 3 during development and
local testing.

This python is not directly usable with python extension, pip needs to
be installed as user, following:
https://pip.pypa.io/en/stable/installing/#installing-with-get-pip-py

by logging the process output

so that frontend requests are requested as theia computer partition.
Practically this means that if theia is installed on slapos master,
frontend requests for slapos inside theia partition will be requested as
this theia instance.

When updated to 4.8.1 the cursor "shadow" rendering is incorrect

workaround for https://github.com/eclipse-theia/theia/issues/8158

So that parts are shared when we install ERP5 in theia

Not much tested but it looks working

Even if we don't use this, the debug pane cause an error when jdk is not
installed

Some optional extensions installable from the registry (like the XML
supports from redhat) also need java and it's better to have something
to edit XML

extracted from nexedi/slapos!735

Explicitly build with libcap-ng instead of depending on presence of the
development library on the host.

Also fix the way of disabling tinfo, there was warning at the end of
configure saying this option is not used

extracted from nexedi/slapos!735
and updated to 0.11

Instead of passing various kedifa information to the profile generating
configuration use section kedifa-configuration and access later such grouped
values.

In context of frontend node reuse passed directory section to slave
configuration to improve readability and simplify future enhancements.

This reverts commit 92fd6909, which
incorrectly added test assertion files with 'test.test'.

Caddy's proxy stanza for defined path with spaces sometimes is working when
it's done like this:

  proxy /path with_spaces ip:port

It happens, that few first requests after starting Caddy it's working, but
then it fails with error message like:

  dial tcp: lookup with_spaces on ip: no such host

So to stabilise situation now paths are generated like:

  proxy "/path with_spaces" ip:port

ssl_proxy_ca_crt can be just empty value, and that's not acceptable.

Use @@LOCATION@@ template to provide proper prefix path.

These changes allow to build SlapOS on Debian Buster ppc64el.

The PowerPC 64-bits little endian platform appeared more recently into autoconf and therefore needed updated `config.sub` and `config.guess` files.

Somehow these only needed to be patched on autoconf itself which is quite dated (2012), and libyaml that does not ship it's own `config.sub` and `config.guess` files. Other components built fine out of the box.

`config.sub` and `config.guess` files were taken from Debian Buster itself. More information at: https://wiki.debian.org/AutoTools/autoconf

**This merge request would have to be backported to previous releases in the case components reference older releases of SlapOS, which, if I understand correctly, is the case some times.**

See merge request nexedi/slapos!780

autoconf and libyaml needed updated config.sub and config.guess files
on ppc64le.

gnu-config component was created to centralize updated config.sub and
config.guess files. autoconf and libyaml now extend gnu-config and
overwrite their bundled config.guess and config.sub with gnu-config's.

in the future, any component can extend gnu-config to update it's own
config.sub and config.guess files if necessary.

monitor app shows:

![monoring app showing /log url](/uploads/dbb22484f79ed1538a308c640d74c3dc/image.png)

but this URL can not be accessed:

![/log URL unauthorized](/uploads/cf74f2d8bb867123c39264d8f7d9de74/image.png)

The correct URL looks to be this:

![/share/private/log is OK](/uploads/4775d5d3841d8ffa68d67f2cf2b87b22/image.png)

See merge request nexedi/slapos!785

This MR includes the following steps:
1. Target Python 3
2. Upgrade powerdns from version 3.3.1 to version 4.2.1 --- which also means...
3. Rework the configuration to support the [new GeoIP backend config format](https://doc.powerdns.com/authoritative/backends/geoip.html)

See the commit messages for more detail.

Note: EDNS Client Subnet extension is enabled.

See merge request nexedi/slapos!764

With the recent powerdns upgrade, the GeoIP backend uses a new config
format, see zones-file.yml.jinja2.

zz.countries.nexedi.dk.rbldnsd (which maps IPs to countries) is replaced
by GeoLite2-Country.mmdb(1) (which maps IPs to countries & continents).

Note: zz.countries.nexedi.dk.rbldnsd is not deleted (yet?); it is parsed
to keep information about China and its IP ranges grouped by ISP.

cdn.conf.in (which maps RR(s) to countries) is dropped; it is replaced
by an equivalent mapping done inside zones-file.yml.jinja2.

Also, EDNS Client Subnet extension is enabled.

---
(1): Added in previous commit.

Note: Only boost>=1.35 and openssl are required to build powerdns from
source; ragel, bison and flex are also required if building from git.
See https://doc.powerdns.com/authoritative/appendices/compiling.html#dependencies

See merge request nexedi/slapos!781