Generalize FailedBatchDeleteException so we can reuse it for other failed batch operations.
Add exception to appropriate GenericDAO method and implementations.
Minor parameter name clean up for other exceptions.
Add UpdateObject and related classes to core DAO module.
Rename Dirtyable to Persistable (along with cascading changes).
Add support for ReferenceSets to DynamoDB module.
Modify FailedBatchException to take a Map instead of a List.