Introduced sparseClustering3 algorithm

This algorithm is intended to replace sparse 1 and 2 clustering. You can check it out by setting the clustering algorithm to  SparseCluster3, i.e.:

```<parameter name="ZSClusteringAlgo" type="string" value="SparseCluster3"/>```

There are no cuts which can currently be set by the user (this will be extended as soon as it replaces the other algorithms).