Introduce it as normal API of Software Instance since the structure is well-defined so we can move away from SlapTool

    This aims to define an kind of export feature used widely on SlapTool, which is eventually used by the node on the proper context. So it would be reusable accross multiples API's.

   Move away part of SlapTool code into a Mixin specific to fill and get Computer Information cache

both signature-private-key-file and signature_private_key_file works for
slapos.core but only signature-private-key-file works in slapcache and
slapos.libnetworkcache

This fixes a bug when the program output contain some ansi code, like
the \e[0;31m ansi code to display text in color on the terminal. These
characters are not allowed in XML so if they end up in the XML-RPC
messages this cause the underlying expat library to complain that the
stream is not well-formed (invalid token).

Fortunately, supervisor supports this and has a `strip_ansi` option that
we can set in the config to prevent these problems.

  It relies on Person_requestSupport now

We just relax the conditions to have an OS match.

 * consider raspbian as a debian
 * never set id

After the change to distro.linux_distribution() in
425f5bb7, raspbian is correctly detected
and id is set, see the execution of both functions on raspbian:

>>> platform.linux_distribution('', '', '', platform._supported_dists, 1)
('debian', '10.11', '')

>>> distro.linux_distribution(full_distribution_name=False)
('raspbian', '10', 'buster')

slapproxy, just like reference SlapOS Master, has to transmit important
partition parameters, in order to really support all features expected by the
software releases.

platform.linux_distribution() is deprecated since Python3.5 and it's
removed altogether in Python 3.8.

This more or less reverts 75b2d79c.

We don't need anymore the patch for Ubuntu as it is correctly supported
in distro module.

This commit reverts ddd77222.

The goal is to fix nexedi/slapos.buildout!25 (comment 148861)

os.environ is a special mapping object that transparently modifies the
actual environment and we should never make os.environ make point to
something else (see
nexedi/slapos.buildout!25 (comment 149333)
and https://docs.python.org/3/library/os.html#os.environ)

Instead change the environment only when calling SlapPopen. We will see
if the problems fixed by ddd77222 appear
again...

See merge request nexedi/slapos.core!360

See merge request nexedi/slapos.core!356

   This introduce API for request support and add events on Support Requests

   Used to create support requests to send users notifications.

   This creates a Support Request

fixup for a8917a3c

Check that promises run with the instance's python are logged properly.

Promises processed using the instance's python in a subprocess were
logged to the console but not to the logfile passed by `--logfile`.

To fix this the output of the promise is now captured and forwarded
to slapgrid's logger in real-time using SlapPopen.

fixup for a8917a3c

See merge request nexedi/slapos.core!365

The option use_unique_local_address was added in
de11308a but was already broken because
2 different names were used for the option:
 * use_unique_local_address_block
 * use_unique_local_address

There was a tentative fix in c09214cb
but the option name in slapos.cfg.example was never fixed.

The c647aab4 dropped _storeLastData, so
follow-up changes here.

Wrong object used resulted with non working SupportRequest_recheckMonitoring
on Compute Node.

   It wasn't working properly, let's reintroduce once it better tested.