This code is a very old fork of batching code from the Zope project. The
z3c.batching package (http://pypi.python.org/pypi/z3c.batching) appears to
have evolved from the same, or very similar, source. Ideally, we will be able
to change lazr.batchnavigator to depend on z3c.batching, perhaps contributing
to that package any necessary changes for our usage needs.
