Batch ranking query

major update that adds an UpdateLog that is automatically replayed in case of a hard system fall

Alow construction of BatchKNNQueryOperation using any Iterator,
not only StreamGenericAbstractObjectIterator

Master

 * removing one constructor from JoinQO that had the same number of arguments as other constructor that was used more often

 * randompivotchooser marked as deprecated, because it does not select the pivots uniformly; it took me about 8 hours of my time

 * LocatorQueryOperation now allows more than one query locator
 * RefineCandidate operation generalized to be applicable also to multi-query operations
 * KNN RankByLocator allows more than one query locator
 * added new multi-query average distances (geometric mean and harmonic mean)

 * adding new options in aggregation function

* Added a few tests for the sorting iterator

* Updated sorted iterator to incorporate original intersection computation (this will be removed in the future)
* Added implementations of Cosine and Jaccard distance functions for text processing

 * WARNING: this cosine distance is not metric