Also export shortcuts for the various metrics in EDdA.classification

EDdA/classification/__init__.py

 from EDdA.classification.nGramsFrequencies import topNGrams
-from EDdA.classification.classSimilarities import confusionMatrix, toPNG, metrics
+from EDdA.classification.classSimilarities \
+        import colinearity, confusionMatrix, keysIntersection, toPNG, metrics