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 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
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.

Before slapos commit a184cca8b (Try to reuse existing file to avoid
excessive IO on update + other minor optimisations, 2019-06-17), which
started to be used in profiles in 65acdca0d (Release slapos.cookbook
(1.0.118), 2019-08-13), the promise plugins did not contain

    import sys
    sys.path[0:0] = (..., )

but there was an extra import statement:

    import sys
    import json
    sys.path[0:0] = (..., )

slapos.core >= 1.7 was not able to process such promises, because the
code introspecting these promises assumed that the second node of the
AST was the assignment, which is incorrect in the old promises because
it was another import.

To accomodate both cases, use the value from the first assignment.

We also change to use ast.literal_eval for safety.

This method returns the class of computer used for the test, then
it's easier for test subclasses to use a computer with different
classes for software and instances.

Use this in TestSlapgridPluginPromiseWithInstancePython, using
subclasses instead of monkey patching should make extending this
test a bit easier