Add documentation regarding revised implementation of 304 (Not Modified) optimization in `RKManagedObjectRequestOperation`
Fix broken test coverage for 304 (Not Modified) optimization
Add test coverage for connection of objects with temporary ID's. closes #1227
Configure `RKManagedObjectImporter` to set the mapper operation instance as the parent operation for the `RKManagedObjectMappingOperationDataSource` instance. This enables relationship connection between objects that are created without an intervening save.