==================
* Added support for Django 3.1
* Dropped support for Python 2.7 and Python 3.4
* Dropped support for Django < 2.2
* Changed the preferred way to do model registration via model inheritance
and ``mptt.AlreadyRegistered``, which is deprecated since django-mptt 0.4
* Use dashed name for django-polymorphic dependency in setup.py
* In ``models.File``, add field ``mime_type`` to store the Content-Type as set by
the browser during file upload
* For extended Django Filer models, adopt the classmethod ``matches_file_type`` to its
new signature, this is a breaking change
* Add attribute ``download`` to the download link in order to offer the file
under its original name