Add SMW\SPARQLStore\FusekiHttpDatabaseConnector

- `$smwgSparqlDatabase = 'SMW\SPARQLStore\FusekiHttpDatabaseConnector';`
- Skip tests where `subobjects` are involved (RDF exporter doesn't support `_SOBJ`)
- Tests: 2031, Assertions: 6018, Failures: 4, Skipped: 75: currently the __regression tests__ create failures due to sparql database is not being reset after each test while most __skipped tests__ are created by a `SQLStore` check

Thanks to Timothys for the [0] installation description.

[0] http://semantic-mediawiki.org/wiki/Help:Using_SPARQL_and_RDF_stores#Jena_Fuseki

Relates to #337 
I guess this is not a new setting? Generally it is not nice to point to a class here. User config will break if we move things