* Added support for Environment(..., readahead=False).
* LMDB 0.9.9 is now bundled.
* Many Python 2.5 and 3.x fixes were made. Future changes are automatically
tested via Travis CI <https://travis-ci.org/dw/py-lmdb>.
* When multiple cursors exist, and one cursor performs a mutation,
remaining cursors may have returned corrupt results via key(), value(),
or item(). Mutations are now explicitly tracked and cause the cursor's
data to be refreshed in this case.
* setup.py was adjusted to ensure the distutils default of '-DNDEBUG' is never
defined while building LMDB. This caused many important checks in the engine
to be disabled.
* The old 'transactionless' API was removed. A future version may support the
same API, but the implementation will be different.
* Transaction.pop() and Cursor.pop() helpers added, to complement
Transaction.replace() and Cursor.replace().