- Refactor so that we can create RepositoryState in one place and then reference to it from JpaRepositoryTransition impls. - New common top class BaseRepositoryEntity for entities - Change RepositoryState and RepositoryTransition to be abstract classes instead of interfaces. - New custom StateMachineJackson2RepositoryPopulatorFactoryBean and StateMachineJackson2ResourceReader handling json refs. - Relates to #262