Django-content-editor

===================

- Fixed our use of internal API of ``forms.Media`` that will be removed
in Django 2.0.
- Fixed an elusive bug with our formsets handling. Newly added content
blocks have to be saved before they can be reordered.
- Fixed a handful of minor CSS bugs.
- Updated the documentation with a few improved recommendations.
- Moved plugin buttons before the dropdown.
- Removed the JavaScript's dependency on the exact ``related_name``
value of plugins.

===================

- Moved the ``JS`` form assets helper to django-js-asset_, thereby raising
our own Python code coverage to 100%.
- Added Django 1.11 and Djangomaster to the Travis build.
- Added a tox_ configuration file for building docs and running style
checks and the test suite.
- Added a check which errors if the model registered with the
``ContentEditor`` has no ``regions`` attribute or property.
- Expanded the documentation a bit.
- Fixed occasional problems when sorting by keeping the empty inline
formsets at the end at all times. Thanks to Tom Van Damme for the
contribution!

===================

- Moved the regions inheritance handling from ``contents_for_mptt_item``
to ``contents_for_item`` to make it reusable outside MPTT hierarchies.
- Reworded the introduction to the documentation.

====================

- Changed ``Region`` and ``Template`` to extend
``types.SimpleNamespace`` on Python versions that support this
(>3.3)
- Allowed restricting individual plugin types to a subset of available
regions by setting ``ContentEditorInline.plugins`` to a list of region
keys. Thanks to Tom Van Damme for the contribution!
- Removed Django from ``install_requires`` -- updating
django-content-editor does not necessarily mean users want to update
Django as well.

===================

- Some browsers do not support ``Math.sign``...
- Automatically open the first tab with errors when using tabbed
fieldsets.
- Improve visibility of plugin fieldsets.
- Fixed widgets using their own size in tabbed fieldsets and the
content editor (for example django-versatileimagefield_'s primary
point of interest field).
- Use django.contrib.staticfiles' static URL generation if it is
installed.

===================

- Modified ``PluginRenderer.render`` and
``PluginRenderer.render_content`` to pass on keyword arguments (if
any) to the registered render functions.
- Made tabbed fieldsets' titles stand out if the tab contains invalid fields.