used for rwi ranking.
Main changes:
- introduce a posintext() to access the stored value. This reduces also mem alloc of position array for WordReferenceRow (index access)
- use the positions() array for joined references on multi-word queries if needed (otherwise allow positions() to be null
- adjust assignments and the min() max() and distance() calculation accordingly
Purpose of the test case is to be able to (controlled) analyse the rwi ranking for
multi word searches (with focus on posintext and word-distance ranking)
reger