Avoid overwrapping due to 'pprint' changes in Python 3.4.
Work around ZODB registering level names backwards.

Before Python 3.4, the logging module registered them in both
directions, but quit doing so in 3.4, breaking doctests which expected
to display custom level name ("BLATHER").
Target next release:  4.1.0

- Support new Python versions.

[ci skip]
Add testing support for Python 3.4.