----------------
Workaround identifiers and Django version.
- Features 7 and 8 - ``Signature`` and ``Signer`` models have
``anysign_internal_id`` attribute. It is an unique identifier for signature
or signer on Django side. For use as a "foreign key" in backend's database,
whenever possible. It defaults to an UUID. You may override it with a custom
property if your models already have some UUID.
- Feature 5 - ``Signer`` model has ``signature_backend_id`` attribute. Use it
to store the backend's signer identifier, i.e. signer's identifier in
external database.
- Refactoring 15 - Project repository moved to github.com/novafloss (was
github.com/novapost).
- Refactoring 18 - Tox runs tests for multiple Django version.
- Features 16 and 17 - Tests include Django version 1.7 and 1.8.