ENH: Return attribute n_iter_ for linear models dependent on the enet solver
TST: Added test to check that warm model converges faster than a cold one
TST: Better to test that warm_start runs only once after the prev model has converged
TST: Added test to check that higher alpha converges faster
Added return_n_iter parameter for enet (and lasso) path
FIX potential overflow in _tree.safe_realloc

The multiplication with the sizeof the base type may overflow, esp.
on 32-bit machines with very large datasets, causing the function to
allocate less memory than was intended, without not raising an exception.
Quick fix on grid_scores, updating final value with len(cv)
self.grid_scores_ = scores / len(cv)
test case on rtfe grid_scores fix
MISC: avoid overridding figure in benchs
MISC: <= rather than < in tol check (KMeans)

As reported by @EdwardRaff in #3374
MAINT temporary fix to handle cython renaming in 0.15
MAINT 32 bit unstable tests are unstable on all OSs
[DOC] minor fixes
MAINT typo in Makefile
ENH allow y to be a list in GridSearchCV, cross_val_score and train_test_split.
add test for safe_indexing, add another test for cross_val_score
FIX: Fit the data in tests
Merge pull request #3349 from MechCoder/return_niter

[MRG+1] Return attribute n_iter_ for linear models dependent on the enet solver
BUG: Support array interface
Catch ConvergenceWarning in RandomizedL1