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

clean etherlab: pep8, E203 whitespace before ','

clean etherlab: pep8, E712 comparison to True should be 'if cond is True:' or 'if cond:'

clean etherlab: pep8, E222 multiple spaces after operator

clean etherlab: pep8, E741 ambiguous variable name 'l'

cleanup etherlab: pep8, E306 expected 1 blank line before a nested definition, found X

cleanup etherlab: pep8, E305 expected 2 blank lines after class or function definition, found X

cleanup etherlab: pep8, E201 whitespace after '('

cleanup etherlab: pep8, E202 whitespace before ')'

cleanup etherlab: pep8, E227 missing whitespace around bitwise or shift operator

cleanup etherlab: pep8, E251 unexpected spaces around keyword / parameter equals

cleanup etherlab: pep8, E225 missing whitespace around operator

cleanup etherlab: pep8, E303 too many blank lines (2)

cleanup etherlab: pep8, E231 missing whitespace after ','