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
All `.. code::` instances have been changed to use `.. code-block::`,
and have been properly formatted. The syntax names have been normalised,
so all django templates use the `html+django` syntax, shell commands use
`sh`, and plain text uses `text`.
