Similarly to wendelin.core (see ad34ff4a "wendelin.core: Always use git
checkout for both release and development version") let's switch pygolang to
install via git checkout for both release and tests.

This way we avoid dependency on pypi and will be able to do minor updates
without doing bigger to-pypi releases. Always using git checkout also helps
security a bit because we remove reliance on trust to tarball received from pypi.

/cc @kazuhiko
/reviewed-by @jerome
/reviewed-on !1569

@jerome reports ue/cell/* schemas are not valid JSON and he is right: in
30179be5 I made a mistake to add extra trailing " after propertyOrder
integer value. Fix that.

See merge request nexedi/slapos!1564

  They are json-editor specific features and are not part of the json schema

  By using ref to ../ru/input-schema.json you append oneOf list and dont extend the
  current list.

  This fixes validation properly when oneOf the values are used.

  Done by Thomas Gambier

See merge request !1555

See commit 77eabe12.

BTW, the mentionned 3ff25131d56c7f66066b70191ac828a666600e92
commit was part of nexedi/slapos!1559.

See merge request nexedi/slapos!1549

* Separate root and subscriber from drone SRs to avoid compilation of unnecessary dependencies
* display logs in debug mode

Rename subinstances to avoid conflict. Once a subinstance is allocated on a
computer, changing `sla-computer_guid` does not move the subinstance. Therefore
an instance name containing the computer's guid is necessary.

Fix logs printed out of the logging area

Process all available logs to avoid delay in log printing.

Indicate the time of the last received message in format hh:mm:ss .

Set c-astral SR in its own file and leave the autopilot used blank in software-base.cfg

Set publishing interval to 200 ms so radio network is not overflown

Allow subscribers' network interface to be different from the drones' one

* use the default RSA key length, instead of hardcoding 1024 (too weak) or 2048 (same as the current default).
* use SHA256 in certificates.

See merge request nexedi/slapos!1559

This reverts commit 3ff25131d56c7f66066b70191ac828a666600e92.

by default on riscv architecture, the libffi.so will be placed in
lib/lp64d but everywhere else in buildout (and especially for the
compilation of python3) we expect the lib to be in lib/ directory.