- update to 4.7.1
* Ensure the interface resolution order of all objects is consistent.
See `issue 137 `_.
* Add unsigned variants of the trees. These use the initial "U" for
32-bit data and "Q" for 64-bit data (for "quad", which is similar to
what the C ``printf`` function uses and the Python struct module
uses).
* Fix the value for ``BTrees.OIBTree.using64bits`` when using the pure Python
implementation (PyPy and when ``PURE_PYTHON`` is in the environment).
* Make the errors that are raised when values are out of range more
consistent between Python 2 and Python 3 and between 32-bit and
64-bit variants.
* Make the Bucket types consistent with the BTree types as updated in
versions 4.3.2: Querying for keys with default comparisons or that
are not integers no longer raises ``TypeError``.