added InstanceValidator reference to help

Change-Id: Ie7a785ecaf50c04b7f532a209821e45244217b2b
Reviewed-on: http://gerrit.esdi-community.eu/3194
Reviewed-by: Simon Templer <simon.templer@igd.fraunhofer.de>
Tested-by: Simon Templer <simon.templer@igd.fraunhofer.de>