scikit-learn 0.17 release

MAINT Release 0.17b1

Merge pull request scikit-learn#5411 from lesteve/fix-plot-tomography…

…-l1-reconstruction-example

[MRG] Fix plot_tomography_l1_reconstruction example

REL bump version to 0.16.1, change in documentation.rst, add to news

REL Version 0.16.0 (adjust __version__, links in docs)

0.16.X branching, version 0.16b1

Merge pull request scikit-learn#4352 from amueller/issue-4297-infinit…

…e-isotonic_bak

[MRG + 2] Adding fix for issue scikit-learn#4297, isotonic infinite loop

Release 0.15.2

MAINT preparing the 0.15.1 release

REL: Release 0.15.0