----------------
- Added ``show_language_picker`` as a ``Setting`` object with a default of
``False``.
[reinout]
- Moved language checker over from lizard-ui. That way it can be enabled
through abovementioned ``Setting`` object.
[reinout]
- Added ``language_code`` as a proper ``Setting`` with a default of
``nl``. Better explicit than implicitly falling back on the regular django
``LANG_CODE`` setting.
[reinout]
- Changed the lizard-map locale middleware to look at the
``show_language_picker`` setting. If enabled, we obviously want to use the
user's preferred language. If there is no language picker, we keep returning
the language set in the ``language_code`` setting.
[reinout]