BUG-1436: deprecate IntermediateMapping

IntermediateMapping is only used in CompositeNode-related codecs and
thus is scheduled to be removed at the same time as CompositeNodes.

Change-Id: Ifff06e62441e5f8cc2eac069145389201f369493
Signed-off-by: Robert Varga <rovarga@cisco.com>
Merge "BUG-1436: deprecate IntermediateMapping"