Node.ext.ugm

----------------

- Nothing changed yet.

----------------

- Extend ``node.ext.ugm.interfaces.IUser`` by ``expires`` and ``expired``
attributes and provide default values on ``node.ext.ugm._api.User``.
[rnix]

- Implement ``expires`` and ``expired`` on ``node.ext.ugm.file.UserBehavior``.
Extend ``node.ext.ugm.file.UgmBehavior`` by ``user_expires_attr`` which
enables used expiration support.
[rnix]

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- Remove usage of ``Nodespaces`` behavior.
[rnix]

- Replace deprecated use of ``Storage`` by ``MappingStorage``.
[rnix]

- Replace deprecated use of ``Nodify`` by ``MappingNode``.
[rnix]

- Replace deprecated use of ``NodeChildValidate`` by ``MappingConstraints``.
[rnix]

- Replace deprecated use of ``Adopt`` by ``MappingAdopt``.
[rnix]

- Replace deprecated use of ``allow_non_node_children`` by ``child_constraints``.
[rnix]

-------------------

- Rename deprecated ``FileStorage.allow_non_node_childs`` to
``allow_non_node_children``
[rnix]

-------------------

- ``node.ext.ugm.file.GroupBehavior.add`` properly raises ``KeyError`` if given
user not exists.
[rnix]

- Also call parent in ``node.ext.ugm.file.UserBehavior.__call__`` and
``node.ext.ugm.file.GroupBehavior.__call__`` if not called from parent.
[rnix]

- ``node.ext.ugm.file.FileStorage.invalidate`` gets set with
``plumber.override`` instead of ``plumber.default`` to work on
``node.ext.ugm.file.Users`` and ``node.ext.ugm.file.Groups``.
[rnix]

- ``node.ext.ugm.file.FileStorage`` values can be ``node.utils.UNSET``.
[rnix]

-------------------

- Implement ``invalidate`` on ``node.ext.ugm.file.Ugm``.
[rnix, 2020-05-16]

- ``node.ext.ugm.interfaces.IUgm`` inherits from
``node.interfaces.IInvalidate`` now.
[rnix, 2020-05-16]

- Describe behavior of ``__getitem__``, ``__delitem__`` and ``__iter__`` on
``IGroup`` interface.
[rnix, 2020-05-11]

- Fix file based ``GroupBehavior.__getitem__`` to properly raise ``KeyError``
when accessing user which is no member of group.
[rnix, 2020-05-11]

- Make clear on ``User`` and ``Group`` behaviors which not impelented functions
are abstract and which are not supported.
[rnix, 2020-05-11]