Fixes #3560
This reverts their language to the site-wide default.
Also, redirect to the account index on submission, for consistency with other views (and to prevent 'form resubmission' alerts when navigating browser history).
This allows a new page to inherit values from its parent page by
overriding `base_form_class`, or to modify the form based on some
conditions of its parent.
Datetime-related tests are intermittently failing on Appveyor; the error at https://ci.appveyor.com/project/wagtail/wagtail/build/1.0.141/job/30t7t1ydh78gupie implies that this is due to invalid datetime formats being returned from submittable_timestamp. Using strftime means that we're not reliant on the return value of str(timestamp) being formatted in a specific way.
We have to run python manage.py migrate once, in order to create the necessary tables for the postgres search backend.
Otherwise we get an error, as the insert in the table is not possible.
At the moment, Wagtail redirects all requests (including AJAX) to the
login view. This is not usually the expected thing to do for AJAX and can
lead to the login page being nested in a component somewhere (which
looks horrible).
This changes the behaviour so requests that come from AJAX are given a
plain 403 error. This allows the code that performed the request to
handle the issue properly.
added prefered language field and migration
added form and view to select prefered language
Added some tests
modified tests
fix styleguide errors
activate middleware only for authenticated users
fixed typos
fixed test undoing language preferences
fixed lint issues
fixed tests
fixed message
change behaviour and more test added
added utf8 coding
[skip ci] initial documentation for preferred language
added contributor
refactor get_available_admin_languages
refactor get_available_admin_languages
make language name language aware
translate notifications to recipient language
make language name language aware
fixed lint
