Fix bug identified in #1817, comment 17340049
Release the GIL at tree building time
Put more code under non-GIL block
Update dict_learning.py

Added parallelisation for online dictionnary learning algorithm.
Merge pull request #2533 from samuelstjean/patch-1

Update dict_learning.py
DOC norm optimizations in what's new

As requested by @ogrisel.
MAINT remove mlcomp document classif. example

It's redundant given the other 20newsgroups example.
ENH optimize one more sq. distance in k-means
Merge pull request #2528 from ogrisel/tree-nogil

[MRG] Release the GIL at tree building time
Add implementation of RANSAC algorithm
Add ransac function to __init__.py of utils package
Fix bug in residual determination
Add step-by-step description of RANSAC algorithm
Add parameter description to RANSAC and modify API
Add example plot script for RANSAC
Add simple RANSAC unit test
Add unit tests for RANSAC is_model_valid and is_data_valid
Add unit tests for RANSAC max_trials option
Return number of trials in RANSAC
Fix n_trials return value and add additional test