Tweak docs, add test cases for mapping a response with a descriptor that does not specify any attributes/relationships
Add support for obtaining a permanent managed object ID for the `targetObject` of an `RKManagedObjectRequestOperation`
Unwind earlier fix for obtaining permanent objectID for targetObject in favor of the overridden setter on RKManagedObjectRequestOperation
Fix RKObjectIsCollectionContainingOnlyManagedObjects function
Merge pull request #1186 from jamesmoschou/collection-of-managed-objects-typechecking-bugfix

Fix RKObjectIsCollectionContainingOnlyManagedObjects function