[RELEASE] 0.18.2 bump version, added whatsnew (scikit-learn#9167)

* bump version, added whatsnew

* pin matplotlib in circle so we don't get 2.0 styles

* fix plot_stock_market.py to work on python2.7 and numpy1.6

* let's try unpinning sphinx for a change.

* don't try to upgrade sphinx-gallery, just port the fix

* clearly not my day

* pin sphinx at 1.4 and docutils at 0.12 and light some incense.

skip tree-test on 32bit

[MRG + 1] More versionadded everywhere! (scikit-learn#7403)

* insert versionadded versionchanged directives in docstrings for 0.18

indicate where exception classes were moved from

* moved versionadded in the proper places

Release 0.18rc2

Release 0.18rc1

Release 0.18rc

Release 0.17.1

MAINT ignore cythonize.dat generated by master branch

scikit-learn Debian release 0.17.0-4

scikit-learn Debian release 0.17.0-3