Feincms3

~~~~~~~~~~~~~~~~~~~~

- Changed ``Regions``' ``cache_key`` argument handling to allow
disabling caching by returning a falsy value.
- Added the ``feincms3.renderer.render_in_context`` utility.
- Verified compatibility with Django 3.0.
- Made the ``TemplateMixin.template`` property fall back to the first
template in ``TEMPLATES`` if the specific template could not be found
or does not exist.
- Fixed another path uniqueness validation problem where pages having
descendants with static paths could not be saved.

~~~~~~~~~~~~~~~~~~~~

- Changed ``app_instance_namespace`` to ``blank=True`` to make it clear
what the default value is.
- Fixed a possible path uniqueness problem with descendants with static
paths.
- Dropped Python 3.4 compatibility.

~~~~~~~~~~~~~~~~~~~~

- Added copying of ``handler400``, ``handler403``, ``handler404`` and
``handler500`` from ``ROOT_URLCONF`` to the URLconf module created by
``apps_urlconf``.


Removed all deprecated features
-------------------------------

- The ``AppsMiddleware`` alias for ``apps_middleware`` has been removed.
- The ``feincms3.incubator`` module has has been removed including
subrenderers.
- The ``depth`` and ``cte_path`` attributes of ``AbstractPage`` have
been removed. Those helped with the transition from django-cte-forest
to django-tree-queries almost one year ago.
- ``TemplatePluginRenderer.regions()`` and ``feincms3.renderer.Regions``
are replaced by ``feincms3.regions.Regions``. Region timeouts must be
specified when instantiating the ``feincms3.regions.Regions`` object
and cannot be specified when rendering individual regions anymore.
- The ``feincms3_apps`` and ``feincms3_renderer`` template tag libraries
have been replaced by a single ``feincms3`` tag library.

~~~~~~~~~~~~~~~~~~~~

- Fixed overflowing tree structure boxes in the ``TreeAdmin``.
- Switched to emitting ``DeprecationWarning`` warnings not ``Warning``,
even though their visibility sucks.
- Added a ``languages`` argument to ``reverse_app`` which allows
overriding languages and their order.
- Made ``TreeAdmin`` and ``MoveForm`` only require that the default
manager is a ``TreeQuerySet`` and not that the model itself also
extends ``TreeNode``.
- Made ``plugin_ckeditor.js``\'s dependency on ``django.jQuery``
explicit. This is necessary for Django 2.2's new ``Media.merge``
algorithm.

~~~~~~~~~~~~~~~~~~~~

- Deprecated the ``feincms3_apps`` and ``feincms3_renderer`` template
tag library. ``render_region`` and ``reverse_app`` have been made
available as ``feincms3``. The ``render_plugin`` and
``render_plugins`` tags will be removed completely.
- Changed ``feincms3.regions.matches`` to the effect that ``None`` has
to be provided explicitly as an allowed subregion if items with no
``subregion`` attribute should be matched too.
- Removed an use of six which is unnecessary now that we only support
Python 3.
- Imported ``lru_cache`` from the Python library.
- Replaced ``concrete_model`` calls to determine the concrete subclass
of ``AppsMixin`` with capturing the model instance locally in the
``class_prepared`` signal handler.
- Removed the now unused ``concrete_model`` and ``iterate_subclasses``
utilities.
- Replaced two more occurrences of ``.objects`` with
``._default_manager``.
- Deprecated accessing the backwards compatibility properties
``AbstractPage.depth`` and ``AbstractPage.cte_path``.
- Deprecated ``feincms3.apps.AppsMiddleware`` in favor of
``feincms3.apps.apps_middleware``.

~~~~~~~~~~~~~~~~~~~~

- **(not yet) BACKWARDS INCOMPATIBLE** Deprecated
``TemplatePluginRenderer``'s ``regions`` method, the ``regions_class``
attribute and ``feincms3.renderer.Regions``. Introduce the more
versatile ``feincms3.regions.Regions`` class instead which also
replaces the ``feincms3.incubator.subrenderer`` functionality and does
not suffer from a software design problem where the regions and the
renderer classes knew too much about each other. This has been
bothering me for a long time already but became impossible to overlook
in the subrenderer implementation.
- Updated the Travis CI matrix to cover more versions of Django and
Python while reducing the total job count to speed up builds.
- Made the default textarea used for editing the HTML plugin smaller.
- Added documentation for the new ``reenter`` subrenderer hook.
- Augmented the snippet plugin with a way to specify a template-specific
plugin context callable.