Rollback some changes now that Python persistent handles registering objects during __setstate__ the same way as C persistent.

Fix unpickling POSError subclasses under PyPy. This fixes a bunch of '<Unprintable POSKeyError>' tests in ZEO.

The Python persistent implementation has caught up enough with the C version that we don't need to list extra special names that shouldn't re-wake Broken objects.

Fix the functional blob tests under PyPy/pure-python by avoiding spuriously registering Blob objects as modified each time they are loaded from cache. This is something of a difference in behaviour between the C and Python implementations, but it's also arguably a bug in the Blob class.

The changes were mostly in the Persistent module. Here, the changes were minimal:

- Introduce zodbpickle for PyPy and Python 2.7 to fix noload.

- Centralize the construction of Picklers/Unpicklers to account for the differences between Python2/3/zodbpickle.

- A few extra gc.collect() calls.

- Some minor printing differences in the doctests due to the Python implementation of BTrees.

Checkpoint on ZODB under PyPy: 25 failures, 25 errors (needs my persistent fork). Many of them are printing differences, some have to do with the Python persistent implementation, especially PickleCache

Use zodbpickle under pypy and 2.7 for a working noload. Also add pypy to tox so I can start testing it.

Fix manifest and setup

- include .coveragerc
- Add author, author_email, keywords

    $ check-manifest
    lists of files in version control and sdist match
    $ pyroma .
    ------------------------------
    Checking .
    Found ZODB
    ------------------------------
    Final rating: 10/10
    Your cheese is so fresh most people think it's a cream: Mascarpone
    ------------------------------

Add tests for repozo's parseargs().

Fixes https://github.com/zopefoundation/ZODB/issues/28

It didn't work for me, because nose would crawl inside manual_tests, try
to run test_fstest.py, and fail (because that test is manual and
requires extra setup, like putting fstest.py on PYTHONPATH).

I also don't think that we want to exclude test layers from coverage
measurements (nose doesn't support them).

This change makes 'tox -e coverage' use zope.testrunner like it does for
regular tests.

See https://github.com/zopefoundation/zope.testrunner/pull/19

Cleaned up exception logging and changed pins

- Always use logger.exception rather than logging.error when logging
  exceptions ar the error level.

- Fixed an incorrect call to logging.exceotion (like PR #26, but better :).

- Removed dependency pins and added one to overcome some breakage in
  zope.testrunner.

None of this seems to be CHANGES worthy.

Conflicts:
	CHANGES.rst
	setup.py

We have been registering our custom level names ("BLATHER", "TRACE) in the
wrong order since 2004.  Before Python 3.4, the stdlib ``logging`` module
masked the error by registering them in *both* directions.

'width=1' causes excess wrapping.