Fix Operation failure by implementing clone() method for ClassifierKmeansSamInc

Since we introduced stronger type constraints, only an instance of classes who implement ISamarahCompatibleClassifier can invoke split, merger, reclass.

When we launch such an operation(split, merge, reclass), a copy of the initial classifier will be created to run the operation. Since ClassifierKmeansSamInc doesn't implement its proper Clone() method, its parent's Clone() method is called. We will thus have a new instance of KmeansClassifier which is not an instance of ISamarahCompatibleClassifier. Thus the operation fails.