* 20080327: Add a parameter to DBEnv.log_flush().

* 20080402: If a prepared/recovered transaction is garbaged collected,
  we leak transactions. Can we call "discard" in a safe way?.

* 20080403: If an exception is raised in a thread in the TestSuite, we
  pass the test. Bad!.

* 20080403: Write a test for MVCC.

* 20080403: We should recreate the test data directory in every
  execution, and delete it when finished.

* 20080403: "txn_stat" provides a list of active transactions. Export it
  to Python.

