also str representation of unicode character is different.

page templates unicode resolver already takes care of coercing when
needed and this is directly compatible with python2 and python3
Co-authored-by: Kazuhiko SHIOZAKI <kazuhiko@nexedi.com>

This only works on python2

for same reason as the xhtml_style version, there is no problem with
having more than one listbox, see d2dedca3 (core: remove useless log
in Base_callDialogMethod, 2020-07-03)

This prevents one failing test to make all subsequent tests to fail

this is removed from python3, it was not so useful here either

use sys.maxsize, see discussion on
nexedi/erp5!1751 (comment 203735)

assertCountEqual is the new python3 name.

Implement this in backportUnittest.py and also move the existing similar
patches (assertRaisesRegex and assertRegex).

  - move the logic of uploading to WebDAV server here instead of the
 generated bin/runUnitTest wrapper
  - run a new `coverage_report` which will
    - download all coverage data from WebDAV server
    - combine the data
    - run html report, saved in log folder
    - print text output in the text output.

This `coverage_report` test waits for other tests to finish uploading
data, we could extend test node distributor to distribute this test at
the end.

See merge request !1933

See merge request nexedi/erp5!1903

Move `spawnDrone` function (where user code is evaluated) and rename
used variables to avoid conflicts with the variables used by the user.
Previously if an user would have assign a value to `i` without declaring
the variable first, it would not have thrown any error as `i` was
already existing in the execution scope.

Even if null speed only makes sense for VTOL vehicules, it is a required testing feature as long as there is no dedicated API.

Loop interval is the time in milliseconds between 2 executions of the
onUpdate function of the user script as well as the periodicity to send
messages to the swarm (which means updating telemetry values).
As this is something we can set in SlapOS mostly to handle bandwith
usage, this must not be linked to the time delta used to update drone
position in the simulation.