scorer: add sample_weight support
MAINT deprecate fit_ovr, fit_ovo, fit_ecoc, predict_ovr, predict_ovo, predict_ecoc and predict_proba_ovr
MAINT split sklearn/metrics/metrics.py
ENH + DOC set a default scorer in the multiclass module
MAINT flatten metrics module and avoid nested bicluster module
DOC typo + not forgetting single output case
Merge pull request #3444 from arjoly/explain-default-score

[MRG+1] ENH + DOC set a default scorer in the multiclass module
ENH in sklearn.metrics set bicluster as a submodule of cluster
FIX import
DOC improve documentation and distinguish each module
DOC link example gallery scripts rather than inline
COSMIT
DOC show referring examples on API reference pages
DOC ensure longer underline
COSMIT Use explicit if/else in scorer
TST default scorers with sample_weight
DOC Update What's New
Merge pull request #3401 from vene/scorer_weights

 [MRG] scorer: add sample_weight support (+test)
ENH add a friendly warnings before deleting the file
Merge pull request #3442 from arjoly/split-metrics-module

[MRG+1] MAINT split sklearn/metrics/metrics.py