make IsotonicRegression pickleable
import pickle
fix svm.fit in feature_stacker.py
FIX: Raise warnings in f_classif a given feature is constant throughout
ENH: More descriptive error which prints the feature indices
cosmit in warning message
Update feature_stacker.py

removed call to "fit" on SVC as pointed out by Roberto
Merge pull request #3480 from dsullivan7/sgd

[WIP] Implementing Averaged SGD
FIX: Thresholded Nearest Centroid fails with non-encoded y
Merge pull request #3746 from MechCoder/nearest_neighbor_manhattan

FIX: Thresholded Nearest Centroid fails with non-encoded y
Bug fix in computing the dataset_centroid in NearestCentroid

A bit more of vectorization and minor code optimizations were added
Merge pull request #3669 from pprett/fix-isotonic-pickling

[MRG+1] Make IsotonicRegression pickleable
ENH: Added median_absolute_error to metrics
DOC: Added doc in model_evaluation.rst
ENH: unit tests for median_absolute_error
Merge pull request #3742 from abhishekkrthakur/master

FIX remove svm.fit in feature_stacker.py
ENH: test_common.py unit tests pass
FIX: Small typo
Merge branch 'master' into median_absolute_error

Conflicts:
	doc/modules/model_evaluation.rst
DOC fix (Nu)SVR attribute shapes in docstring

Fixes #3673. Shapes were probably copy-pasted from (Nu)SVC.
XXX the attributes actually have strange shapes...