* Added a Plasma Data Engine for querying SPARQL endpoints, and returning the results passed to setData() as two strings and a Qt::Variant - the source name, a variable name from the query, followed by a Qt::Variant containing a Soprano::Node as the value of the result.
* The example data engine queries DBPedia for details of the albums for an artist given the artists name.
* So the source might be 'The Velvet Underground', and the results will be all the albums they have released with album name, dbpedia resource urn for the album, and date released. The album name appears both as the source name and an attribute of the source too.
* Enhanced the engineexplorer to work with Qt::Variants containing Soprano::Nodes