fix issue with import module `parse` from lib2to3.pgen2;
import module exactly from plugin folder;
set output stream by argument `stdoutput`.
use abspath instead or relative to "PatternGrammar.txt"
uppercase constant: base_name -> BASE_NAME
remove redirect_std contectmanager
remove debug logging
AutoPep8Command use threads
return back output panel
separate some code into 'common' module
provide threads count by `max-threads` option
use threads