Everywhere including examples, external interop APIs, bindings generators
code and in other valuable places. A couple of `interface{}` usages are
intentionally left in the CHANGELOG.md, documentation and tests.
It's not network-tied any more, network is only needed to
sign/verify. Unfortunately we still have to keep network in consensus data
structures because of dbft library interface.
Frequently one needs to check if struct serializes/deserializes
properly. This commit implements helpers for such cases including:
1. JSON
2. io.Serializable interface
