fix deadlock if method kill() is called after process is already finished

fix pylint py3k conversion warning: "(no-absolute-import) import missing `from __future__ import absolute_import`"

make CanFestival to be at the expected place in bitbucket pipelines container

fix pylint error '(unsubscriptable-object) Value 'X' is unsubscriptable'

fix pylint warning '(bad-continuation) Wrong hanging indentation before block'

force all python source code to have LF line ending

fix pylint warning '(expression-not-assigned) Expression "X" is assigned to nothing'

fix pylint warning '(redefine-in-handler) Redefining name 'X' from outer scope (line Y) in exception handler'

fix displaying result of update check during Beremiz startup

fix pylint warning '(no-init) Class has no __init__ method'

fix pylint error "(undefined-variable) Undefined variable 'X'"

fix problem happend when tests are running under python-coverage

$ python-coverage run ./tests/tools/test_application.py

Exception while connecting LOCAL://!
Traceback (most recent call last):
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 1753, in _Connect
self._SetConnector(connectors.ConnectorFactory(uri, self)
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 1702, in _SetConnector
if connector is not None:
PyAssertionError: C++ assertion "m_window" failed at ../src/gtk/dcclient.cpp(2043) in DoGetSize(): GetSize() doesn't work without window

fix pylint error '(too-many-function-args) Too many positional arguments for function call'

fix pylint error '(import-error) Unable to import X'

fix pylint error '(no-self-argument) Method should have "self" as first argument'