Add Jackson 2 support while retaining backward compatibility as much as possible. Introduce a new abstraction for JSON conversion. JIRA: https://jira.springsource.org/browse/INT-2831 INT-2831: Polishing * remove `JsonObjectMapperFactoryBean` * add @Deprecated constructors to `ObjectToJsonTransformer` and `JsonToObjectTransformer` Polishing Docs, compiler warnings.