DOC improve documentation and distinguish each module

Author: arjoly

sklearn/metrics/classification.py

@@ -1,4 +1,4 @@
-"""Utilities to evaluate the predictive performance of models
+"""Metrics to assess performance on classification task given classe prediction
 
 Functions named as ``*_score`` return a scalar value to maximize: the higher
 the better

sklearn/metrics/ranking.py

@@ -1,4 +1,4 @@
-"""Utilities to evaluate the predictive performance of models
+"""Metrics to assess performance on classification task given scores
 
 Functions named as ``*_score`` return a scalar value to maximize: the higher
 the better

sklearn/metrics/regression.py

@@ -1,5 +1,4 @@
-# -*- coding: utf-8 -*-
-"""Utilities to evaluate the predictive performance of models in regression
+"""Metrics to assess performance on regression task
 
 Functions named as ``*_score`` return a scalar value to maximize: the higher
 the better
@@ -12,7 +11,7 @@
 #          Mathieu Blondel <[email protected]>
 #          Olivier Grisel <[email protected]>
 #          Arnaud Joly <[email protected]>
-#          Jochen Wersdörfer <[email protected]>
+#          Jochen Wersdorfer <[email protected]>
 #          Lars Buitinck <[email protected]>
 #          Joel Nothman <[email protected]>
 #          Noel Dawe <[email protected]>