Zope.schema

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

- Make sure that the title for ``IObject.validate_invariants`` is a unicode
string.

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

- Fix ``SimpleTerm`` token for non-ASCII bytes values.

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

- Make ``NativeString`` and ``NativeStringLine`` distinct types that
implement the newly-distinct interfaces ``INativeString`` and
``INativeStringLine``. Previously these were just aliases for either
``Text`` (on Python 3) or ``Bytes`` (on Python 2).

- Fix ``Field.getDoc()`` when ``value_type`` or ``key_type`` is
present. Previously it could produce ReST that generated Sphinx
warnings. See `issue 76 <https://github.com/zopefoundation/zope.schema/issues/76>`_.

- Make ``DottedName`` accept leading underscores for each segment.

- Add ``PythonIdentifier``, which accepts one segment of a dotted
name, e.g., a python variable or class.

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

- Add the interface ``IFromBytes``, which is implemented by the
numeric and bytes fields, as well as ``URI``, ``DottedName``, and
``Id``.

- Fix passing ``None`` as the description to a field constructor. See
`issue 69 <https://github.com/zopefoundation/zope.schema/issues/69>`_.

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

- Make ``WrongType`` have an ``expected_type`` field.

- Add ``NotAnInterface``, an exception derived from ``WrongType`` and
``SchemaNotProvided`` and raised by the constructor of ``Object``
and when validation fails for ``InterfaceField``.

- Give ``SchemaNotProvided`` a ``schema`` field.

- Give ``WrongContainedType`` an ``errors`` list.

- Give ``TooShort``, ``TooLong``, ``TooBig`` and ``TooSmall`` a
``bound`` field and the common superclasses ``LenOutOfBounds``,
``OrderableOutOfBounds``, respectively, both of which inherit from
``OutOfBounds``.

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

- Fix checking a field's constraint to set the ``field`` and ``value``
properties if the constraint raises a ``ValidationError``. See
`issue 66
<https://github.com/zopefoundation/zope.schema/issues/66>`_.