Added
- `force_rollback` is now a descriptor returning an extensive ForceRollback object.
- Setting True, False, None is now possible for overwriting the value/resetting to the initial value (None).
- Deleting it resets it to the initial value.
- Its trueness value evaluates to the current value, context-sensitive.
- It still can be used as a contextmanager for temporary overwrites.
Fixed
- Fixed refcount for global connections.
Changed
- `connect`/`disconnect` calls are now refcounted. Nesting is now supported.
- ACTIVE_TRANSACTIONS dict is not replaced anymore when initialized.