Partial fix for Bug 1256

Partial fix for Bug 1256

Patch 0e12a849d33ae3ca3d1a8e2e281e6eac2cc13373 introduced a test for data normalization
that contained comparators for two kinds of nodes (LegacyNodeData) and (Node<?>) that
provided only a partial ordering of nodes and also failed to obey the semantics of
comparators when it comes to equality.

The result is that several tests were not fully specified and while the appear to run
correctly on Windows and Linux, on recent MacOS versions the ambiguity caused the tests
to fail.

This patch fixes the problem as long as only SimpleNodes and CompositeNodes are used.

Change-Id: If5175025fb97e7b8ddb799b27ad7ae9b5026172d
Signed-off-by: Colin Dixon <colin@colindixon.com>