fix pylint warning '(misplaced-bare-raise) The raise statement is not inside an except clause'

fix format string argument error found by pylint '(too-many-format-args) Too many arguments for format string'

fix pylint warning '(wrong-import-position) Import "import X" should be placed at the top of the module'

fix pylint warning '(import-self) Module import itself'

remove old code useless code found by pylint "(unnecessary-pass) Unnecessary pass statement"

fix error found by pylint 'W0104(pointless-statement) Statement seems to have no effect'

fix pylint warning "(undefined-loop-variable) Using possibly undefined loop variable 'X'"

fix pylint warning 'C0112(empty-docstring) Empty function docstring'

fix pylint warning "(relative-import) Relative import 'Y', should be 'X.Y'"

fix pylint warning '(dangerous-default-value) Dangerous default value {} as argument'

fix pylint warning '(old-style-class) Old-style class defined.'

This warning is ignored for classes from PyJSLib, because library
overrides base object class.

fix pylint warning '(unused-import), Unused import connectors'