Add a few isCancelled checks to ensure we are not performing unnecessary work after being cancelled.
Add more cancellation backstopping to avoid `NSObjectInaccessibleException` crashes when executing `RKManagedObjectRequestOperation` instances that have been cancelled and the Core Data environment has shifted underneath them (i.e. records have been deleted from the store)
Merge branch 'development' into zerista
Go back to old behavior - fixing in a different way.