This is/was an attempt to be secure against malicious streams, but as Kryo is just a temporary bit of scaffolding and isn't intended to be actually used in any real product, it was just a waste of time and the registration requirement was getting increasingly awkward.
- Use the OpaqueBytes wrapper (a box for byte[]) inside TimestampedWireTransaction to avoid array comparison issues.
- Introduce a few utility functions to make OpaqueBytes less painful.
- Make StateAndRef serialisable
- Introduce the notion of an OwnedState which abstracts out the owner field.
