Differences between 0.1 and 0.1.1

- updated to work with SQLAlchemy 0.4.x

Differences between 0.1.1 and 0.1.2

- updated to work with boto 1.x

Differences between 0.1.2 and 0.1.3

- better clean up of file handlers for filesystem based storage
  and caching (per Larry Meyn)

What's new with 0.2.1

 - Cleanup
 - Bunch of suggestions from Kevin Dangoor

What's new with 0.2.2

- remove hardcoded dependencies of dusty antiquity
- allow override of pickle protocol (per Ling Li)

What's new with 0.3.0

- Redis support for store
- Apache Cassandra support for store (deletion is eventually consistent)

What's new with 0.3.1

- fix wrong keyword in store tests (per Ling Li)

What's new with 0.3.2

- make key exceptions work with tuples (per Ling Li)