Add query filter and comparator test

Test run for both `SQLStore` and `Fuseki` equally successful but we have to skip the date constraint test on `Virtuoso` as it returns wrong results [0].

```
SMW\Tests\Integration\Query\ComparatorFilterConditionQueryDBIntegrationTest::testDateConjunctionConstraints with data set #0 (array(SMWDITime, SMWDITime, SMWDITime), array(SMWDITime, SMWDITime, 3, 2, SMW\DIProperty), array(2, array('197001', '197002')))
Date filter constraints do not work properly in Virtuoso

SMW\Tests\Integration\Query\ComparatorFilterConditionQueryDBIntegrationTest::testDateConjunctionConstraints with data set #1 (array(SMWDITime, SMWDITime, SMWDITime), array(SMWDITime, SMWDITime, 8, 7, SMW\DIProperty), array(1, array('1970012')))
Date filter constraints do not work properly in Virtuoso
```

[0] http://semantic-mediawiki.org/wiki/Help:Using_SPARQL_and_RDF_stores#Virtuoso