----------------
- Python 3 Compatibility.
[rnix]
- Convert doctests to unittests.
[rnix]
- Cache results of ``yafowil.utils.get_plugin_names`` by namespace.
[rnix]
- Introduce ``yafowil.base.Factory.clear`` function. Used in tests to prepare
``yafowil.base.factory`` singleton as required.
[rnix]
- Create deepcopy of resources in ``YafowilResources.__init__`` to prevent
modification of the original resource definitions.
[rnix]
- Implement ``ExtractionError.__eq__`` to make them comparable.
[rnix]
- Do not access deprecated ``Exception.message`` any more in
``common.error_renderer``. Add ``msg`` attribute to ``ExtractionError``
directly and use this one to keep error translating sane.
[rnix]
- Add html5 data attribute support to ``form_edit_renderer``.
[rnix]