------------------
- Drop support for Python 3.3.
- Add support for Python 3.6.
- 100% test coverage.
- Remove internal ``_compat`` module in favor of ``six``, which we
already had a dependency on.
- Stop decoding in ASCII (whatever the default codec is) in favor of UTF-8.
- Tighten the interface of
``ILocalErrorReportingUtility.setProperties``. Now
``ignored_exceptions`` is required to be str or byte objects.
Previously any object that could be converted into a text object via
the text constructor was accepted, but this encouraged passing class
objects, when in actuality we need the class *name*.
- Stop ignoring ``KeyboardInterrupt`` exceptions and other similar
``BaseException`` exceptions during the ``raising`` method.