This commit is a rough port to Django 2.1, Python 3 and a Docker based local
development setup. Tests fail/error but migrations and the web frontend are
already runnable. Task queue functionality is untested and translations seem to
have trouble.
This commit adds tests for managemails.forms. A refactoring TODO is
added to MailAddressFieldMixin and pragma: no cover has been added to
code paths not reachable if no new constants are added to the
MAILBOX_OR_FORWARDS constant array.
- implement managemails.forms.ChangeMailboxPasswordForm
- extract code for determining hosting package and customer from URL into
HostingPackageAndCustomerMixin
- implement managemails.views.ChangeMailboxPassword
- add new URL pattern 'change_mailbox_password' to managemails.urls
- add template managemails/mailbox_setpassword.html
- link from template hostingpackages/customerhostingpackage_detail.html to
change_mailbox_password
- add german translation for new strings
- document new feature in changelog
