FIX PLSRegression again supports 1d target

Fixes plot_compare_cross_decomposition example
WEB fix css for new version of sphinx.
Use plot_galler=0 in makefile for sphinx >1.2.3 Also works with 1.2.3
DOC: COSMIT: Naive Bayes long url + PEP8 cleanup

* Put long link to IR-book on its own line to make sure it renders as a
  correct link in the docs.

* Put long ValueError messages that were breaking PEP8 compliance of
  the file `naive_bayes.py` into temporary variables.

Signed-off-by: mr.Shu <mr@shu.io>
Merge pull request #3892 from mrshu/mrshu/naive-bayes-small-fixes

DOC: COSMIT: Naive Bayes long url + PEP8 cleanup
DOC narrative docs for grid search's robustness to failure
DOC fix layout: ensure stable width of documentwrapper
Fix BallTree and KDTree Docs
DOC target URLs on SGD loss / penalty figures
ENH add coverage multilabel ranking metric
Remove copy paste mistake
DOC improve documentation of coverage
TST make separate tests for coverage + remove redundant tests with commons
DOC clarify how ties are broken for coverage_error
ENH add sample_weight support
DOC typo
TST + FIX ensure that it fails if sample_weight has not proper length
DOC more explicit title
Update what's new
Merge pull request #3882 from MechCoder/doc_tree

[MRG] DOC: Fix BallTree and KDTree Docs