Optional property support in parallax navigation

[namedgraph]

Right now "Related results" are rendered from the results of the current container page. That rules out any properties that are not on that page, i.e. optional properties because some instances have them and some don't.

It would be rather simple to generate a SPARQL queries that retrieves all properties of all instances projected by the container, allowing parallax navigation using optional properties as well. The query performance might be a problem though.