Owner references only work within the same namespace (or cluster scope).
Finalizers give us the ability to clean up state in other scopes, where
owner references are not valid.

ChildReconciler can now opt-out of owner references with
SkipOwnerReference, using a child Finalizer implies SkipOwnerReference.
Since we can no longer link parent and child resources via the owner
reference, the child is tracked explicitly and the OurChild method must
be defined and able to uniquely distinguish the child resource that
belongs to the parent from other resources of the same kind.

Signed-off-by: Scott Andrews <andrewssc@vmware.com>

Signed-off-by: Scott Andrews <andrewssc@vmware.com>