grouping test coverage... added a test case

Raphael Troncy just pointed me to a test case for group, which I didn't find covered in the test suite:

prefix lode: <http://linkedevents.org/ontology/>
prefix dc: <http://purl.org/dc/elements/1.1/>
prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>

select ?event ?eventName ?venue ?photo
where {
   ?photo lode:illustrate ?event .
   {
   select ?event ?eventName ?venue
   where {
         ?event dc:title ?eventName .
         ?event lode:atPlace ?venue .
         ?venue rdfs:label "Live Music Hall" .
         }
   }
}
GROUP BY ?event

according to http://www.w3.org/TR/sparql11-query/#aggregateRestrictions this is not allowed.
I added this one and a simplified version of it as group06 and group07 respectively in 
http://www.w3.org/2009/sparql/docs/tests/data-sparql11/grouping/

Axel