Match the C implementation for the way in which _p_jar and _p_oid can be changed. ZODB depends on this.

Support shrinking the Python PickleCache based on a target byte count, and clear out references to ejected objects when done. This makes the ZODB testConnection and testConnectionSavepoint tests pass but is not tested here.

The Python version of PickleCache.minimize does what the C version does and ghosts the evicted objects.

The Python PickleCache is close enough to the C PickleCache that ZODB's testCache passes. Required some small updates and additions to our own test cases; the update_object_size_estimation is not tested here yet.

Fixes zopefoundation/persistent#18 : Make the .raw() and repr() of the Python TimeStamp match the C version in more cases. Also, make the behaviour of comparisons and hashing match as well; test all this.

In the case of a ZODB broken object, the Python persistent implementation needs to bypass the _setattr_ implementation when working with its own internal state variables. This much gets the ZODB broken tests to pass. Need to figure out how to test this locally.

fix test___setstate___interns_dict_keys failure on pypy3

(not using unittest.skipIf because it doesn't exist in python 2.6)

Also enable travis tests for 3.4 and pypy3

Intern keys in `__setstate__`

Refs zopefoundation/persistent#15

See: http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/

Also, work around edge case on Travis where files aren't found.

Exclude interfaces, whose method docstrings confuse the coverage checker.

Downloaded from https://bootstrap.pypa.io/bootstrap-buildout.py.

[ci skip]

The pure-Python Persistent class no longer calls subclass's __setattr__ at instance creation time, just like the C version.