allow a value for anyType properties

refs #626

Change-Id: Ie3f488908db4a280e95494266683f4853e89a5c3
Reviewed-on: http://gerrit.esdi-community.eu/3169
Tested-by: Jenkins <sitemple@igd.fraunhofer.de>
Reviewed-by: Simon Templer <simon.templer@igd.fraunhofer.de>