FIX: numerical instability caused by collapsed allocation of bad clusters to the center of mass
Add precompute_distances option back and export it.
Merge branch 'minibatch-kmeans-optim' of https://github.com/ogrisel/scikit-learn into minibatch-kmeans-optim

Conflicts:
	sklearn/cluster/k_means_.py
COSMIT reorganise utils tests
TST add test for sklearn.utils.extmath.logsum
Address @ogrisel and @amueller's comments.
ENH: Assign chunk of trees to jobs
species datasets commit
example tweaks
FIX: missing import
Cosmit in metrics
BUG: fix bug introduced in fd8c
ENH: Store the full cv_scores in grid_search
clean up species distribution example
DOC: add alpha_ to attributes of LassoLarsIC
COSMIT: utils.fixes: document versions
misc
FIX: fixed link to Virgile in whats_new
randomized_power_iteration -> randomized_range_finder
api: changed pos_label to None for metrics