DOC fix formatting of attributes etc. in docstrings
COSMIT smipler & more robust check in test_kfold_valueerrors

Using assert_warn_message internally cleans the warning
registries making this test more robust to changes in other tests.
DOC fix see also references
DOC move Attributes section to after Parameters and style likewise
Merge pull request #3491 from ogrisel/fix-warning-test-cross-val

[MRG] TST unstable warning test in test_kfold_valueerrors
DOC fix see also reference
DOC fix markup error
MAINT fix prng in test_f_oneway_ints

Not fixing the PRNG cause the test to fail randomly under windows
where the 4 decimals place check can be too strict for some unlucky
random draws of test data.
ENH Stochastic Coordinate Descent for ElasticNet & Lasso
FIX Implemented correct handling of multilabel y in cross_val_score
FIX Support unseen labels LabelBinarizer and test

This fix restores the default behavior of 0.14.1 for backward
compat.
Add sample_weight parameter to metrics.jaccard_similarity_score

 - Include this metric in sample_weight test in tests/test_common.py
MAINT use assert_warns
MAINT Fix regression random projections work sparse matrices
DOC whats_new.rst: missing backported fixes for 0.15.1
fix: i might be undefined
FIX six issue with module imports

Fixes #3518, #3519.

Inspired by Johannes Schönberger's patch to scikit-image,
https://github.com/scikit-image/scikit-image/commit/71743d2d6ff3666c9530278dfd650c2435fa15d9
Max iter param in Liblinear is now softcoded
ENH: Return n_iter_ from liblinear and print convergence warnings
TST: Added test to check ConvergenceWarning