introduction of finalization

app/vkk/migrations/0004_alter_receipt_buper.py

...5_rename_is_closed_periodclosure_is_closed_contributor.py

...grations/0006_periodclosure_is_closed_manager_and_more.py

...orkhours/accounting/projects/project/workhours_sheet.html

app/vkk/templates/vkk/workhours/workhours_sheet.html

app/vkk/templates/vkk/workhours/workhours_sheet_form.html

...ours/accounting/projects/project/export/receipts/forms.py

app/vkk/workhours/accounting/projects/project/urls.py

app/vkk/workhours/accounting/projects/project/views.py

app/vkk/workhours/contributor/views.py

app/vkk/workhours/forms.py

app/vkk/workhours/manager/urls.py

app/vkk/workhours/manager/views.py

app/vkk/workhours/models.py