#523 "add provenance tracking option to custom subject study fields"

See merge request !441

solved other pylint issues, added ignore pragmas where considered, added two more to the list of globally ignored checks E1131 and E1131

adapted code for new version of django two-factor-auth package that comes with breaking changes. see https://github.com/jazzband/django-two-factor-auth/releases/tag/1.14.0