ENH don't use deprecated interface in PPCA & cosmit
FIX issue #1239 when confusion matrix y_true/y_labels has unexpected labels
PEP8
ENH docstring misleading
Merge remote-tracking branch 'upstream/master' into pr/975
Merge branch 'master' into gbrt-interactions

Conflicts:
	sklearn/ensemble/gradient_boosting.py
Merge exthmath tests into the same file.
Add common assertions to sklearn.utils.testing.

The goal is to have all assertions conveniently in one place.
Fix density utility when input is sparse.
Typo.
Fix test failure.

Sorry about that.
Adding Passive Aggressive learning rates
Added documentation to stochastic_gradient
Added to documentation
Added documentation and removed PA
Added tests
COSMIT: spelling correction
Adding example
Added smoothing to example
COSMIT typo