- Default "target entity resolving code" changed slightly. It now uses a global

collection keyed on the entity name. This means that entities can refer to other entities in a different module simply with the target entity name instead of its full path. The full path is only required when there is an ambiguity (ie when there are two classes with the same name in two different modules). Closes #9.

- Added support for SQLAlchemy 0.5, and dropped support for version 0.3 and

earlier.

- The default session (elixir.session) uses sessionmaker() instead of

create_session(), which means it has now the following characteristics:

• autoflush=True
• autocommit=False (with SA 0.5 -- equivalent to transactional=True with SA 0.4)
• autoexpire=True (with SA 0.5).

- removed objectstore and other SA 0.3 (or older) support code.