SPARQLStore / QE / Split conditions, add SparqlConditionBuilder

- Individual condition are moved from SMWSparqlStoreQueryEngine
- Condition buidling has been moved into its own component to aid SRP
- SparqlConditionBuilder now takes in a Description and outputs a
sparql where condition
Merge pull request #383 from SemanticMediaWiki/sparql-qe-condition

SPARQLStore / QE / Split conditions, add SparqlConditionBuilder
SPARQLStore / QE / Count query results

Count query results are returned as an integer which makes it impossible to
return a proper object or for that matter possible errors

- Add `SMWQueryResult::setCountValue`, `SMWQueryResult::getCountValue`
- `SMWQueryProcessor` is modified in away that it detects an integer or object
and acts accordingly