----------------
Breaking changes:
* Make compatible with Zope4 and drop support for Zope 2.
[pbauer]
New features:
* Add compatibility for Python 3 and 2.
[frapell]
* Improve debug mode detection, provide a ZCML feature, and enable when running
tests with '-D'.
[rpatterson]
* Add zope.testrunner support.
[rpatterson]
* Add some missing iPython support for runcall and broken_delete.
[rpatterson]
Bug fixes:
* Apparently the ipdb support only works with ipdb 0.3 or greater.
Added an "ipdb" extra for this requirement.
[rossp]
* Fix ipdb import in zcatalog.py.
[pabo]