cleanup pyc files between running pytest

this is need to avoid problem sometimes tests are run inside docker
container and sometimes local.

Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/_pytest/config/__init__.py", line 409, in _importconftest
mod = conftestpath.pyimport()
File "/usr/lib/python2.7/dist-packages/py/_path/local.py", line 686, in pyimport
raise self.ImportMismatchError(modname, modfile, self)
ImportMismatchError: ('conftest', '/beremiz/tests/tools/conftest.py', local('/home/developer/beremiz/tests/tools/conftest.py'))
ERROR: could not load /home/developer/beremiz/tests/tools/conftest.py

python3 support: pylint, W1612 # (unicode-builtin) unicode built-in referenced

Use multiple processes to speed up pylint

0 will auto-detect the number of processors available to use.
version 1.6.5 (Debian 9.5) hangs for some reason in multi-process mode.

python3 support: pylint, W1613 # (xrange-builtin) xrange built-in referenced

python3 support: pylint, W1648 # (bad-python3-import) Module moved in Python 3

Fixed regression in connecting to LOCAL:// targets

Merge, with surprizingly little conflicts

IDManager : finished Import/Export. Added merging capability to import (asks if particular ID is replaced during import). Added ESC as closing shortcut to IDManager dialog, and adjusted its size.

merge

Update localization template

Fix 'msgid' format string with unnamed arguments cannot be properly localized

Add automatic check for localization strings with multiple unnamed arguments

Improve localization support in etherlab (mostly)

cleanup etherlab: pylint, W0602 (global-variable-not-assigned) Using global for 'X' but no assignment is done

cleanup: pylint, W0109 # (duplicate-key) Duplicate key 'X' in dictionary

Add python3 syntax checking to CI

Fix old style exception raise and exec syntax

Use python 3 compatible exception syntax everywhere

cleanup: pylint, R0123 # (literal-comparison) Comparison to literal

Use predefined constants for PlcStatus instead of string literals

cleanup: pylint, R1704 # (redefined-argument-from-local) Redefining argument with the local name 'Y'

cleanup: pylint, R1701 # (consider-merging-isinstance) Consider merging these isinstance calls to isinstance(CTNLDFLAGS, (str, unicode))

cleanup: pylint, E1304 # (missing-format-string-key) Missing key 'X_name' in format string dictionary

cleanup: pylint, E1300 # (bad-format-character) Unsupported format character '"' (0x22) at index 17

cleanup: pylint, W0111 # (assign-to-new-keyword) Name async will become a keyword in Python 3.7

cleanup: pylint, E1310 (bad-str-strip-call) Suspicious argument in str.strip call

Fix segmentation fault when last lines in text POUs should be highlighted

enable etherlab checks

resort enabled pylint check to move likely-most invasive changes to the end

clean etherlab: pylint, C0330 # (bad-continuation) Wrong hanging indentation before block

clean etherlab: pylint, W0612 # (unused-variable) Unused variable 'X'

clean etherlab: pylint, W1618 # (no-absolute-import) import missing `from __future__ import absolute_import`

clean etherlab: pylint,E0602 # (undefined-variable) Undefined variable 'X'

clean etherlab: pylint, E1136 # (unsubscriptable-object) Value 'X' is unsubscriptable

ignore missing MotionLibrary

to fix pylint error 'E0401 # (import-error) Unable to import 'X'

clean etherlab: pylint, E0611 # (no-name-in-module) No name 'X' in module 'Y'

clean etherlab: pylint, C0123 # (unidiomatic-typecheck) Using type() instead of isinstance() for a typecheck.

clean etherlab: pylint, W0104 # (pointless-statement) Statement seems to have no effect

clean etherlab: pylint, W0631 # (undefined-loop-variable) Using possibly undefined loop variable 'X'

clean etherlab: pylint, C1001 # (old-style-class) Old-style class defined.

clean etherlab: pylint, W0611 # (unused-import) Unused import X

clean etherlab: pylint, E0102 # (function-redefined) method already defined

clean etherlab: pylint, W0105 # (pointless-string-statement) String statement has no effect

clean etherlab: pylint,W0231 # (super-init-not-called) __init__ method from base class is not called

clean etherlab: pylint, C0412 # (ungrouped-imports) Imports from package X are not grouped

clean etherlab: pylint,W0108 # (unnecessary-lambda) Lambda may not be necessary

clean etherlab: pylint, C0411 # (wrong-import-order) standard import "import x" comes before "import y"

clean etherlab: pylint, W0404 # reimported module

check_source.sh: add E301 check to the list of selected PEP8 errors

clean etherlab: pep8, E301 expected 2 blank lines, found 1

clean etherlab: pep8, W503 line break before binary operator

clean etherlab: pep8, E266 too many leading '#' for block comment

clean etherlab: pep8, E122 continuation line missing indentation or outdented

clean etherlab: pep8, W191 indentation contains tabs

clean etherlab: pep8, E211 whitespace before '['

clean etherlab: pep8, E129 visually indented line with same indent as next logical line

clean etherlab: pep8, E127 continuation line over-indented for visual indent

clean etherlab: pep8, E129 visually indented line with same indent as next logical line

clean etherlab: pep8, W602 deprecated form of raising exception

clean etherlab: pep8, W601 .has_key() is deprecated, use 'in'

clean etherlab: pep8, E731 do not assign a lambda expression, use a def