IN PROGRESS - issue OPENFLEXO-424: Use the ontology restriction to
filter elements proposed from the small palette 
https://bugs.openflexo.com/browse/OPENFLEXO-424
Basically adds automatic filtering of LinkScheme according to
restrictions that have been set in the viewpoint ontology (if OWLClass,
if AllValuesFromRestrictionClass, etc... many instanceof)
See also OPENFLEXO-424 for the details.
IMPORTANT: Fix incorrect implementation of isSubConceptOf (already
reported in 1.6)
Merge branch '1.5.1' of ssh://git@github.com/agilebirds/openflexo.git into 1.5.1