[IMP-dev] clustering - consolidation

Hi, Daniel and I discussed a little bit consolidation of clustering things in statistics. I am not touching anything out of the statistics / kmeans module for now, but please tell me if it is agreed that things will work as follows: * The Embedding family of classes (used to embed data in vector form) will remain as is * There will be a "Clustering" class from which all clustering algorithms will derive, with: * constructor that takes either Embedding class, or EmbeddingAdaptor for implicit conversions from e.g., vector form