MAINT warn of future behaviour change proposed in #2610
ENH: Refactoring and optimisation of sparsfuncs.pyx
ENH: Optimise sparsefuncs
a] Removed numpy overhead in finding mean
b] Removed enumerate
c] Added tests to test_sparsefuncs
d] Replaced multiple looping with a single loop
Moved sparsefuncs to sparsefuncs_fast
TST: Added tests for non-CSR/CSR format
DOC heapsort is not stable at all
FIX cross_val_score to take y as a list
FIX cross_val_score to take y as an *optional* list

Sorry for the noise.
Merge pull request #3007 from Manoj-Kumar-S/refactor_sparsefuncs

[MRG+1] ENH: Refactoring and optimisation of sparsfuncs.pyx
FIX: np.random.randint expects signed 32 bit integers under Windows
FIX sed usage in Makefile

Still works on Linux; should work on OS X if I'm to believe the manpage.
FIX: numpy mtrand does not accept Python long instances under Windows
Fixed SelectKBest corner case: k=0

Without this fix k = 0 will have the same behavior as k = 'all' based on how
the array indexing was written.

I've included a test that demonstrates proper behaviour.
Merge pull request #3010 from griffinmyers/fix-select-k-best

Fixed SelectKBest corner case: k=0
FIX: make python setup.py clean also delete __pycache__ folders
FIX: remove casting warning under Python 3
FIX #3014: use a different folder for covtype data under Python 3
FIX: fix build under Python 2.6
BUG FeatureAgglomeration meaningless for no samples

The FeatureAgglomeration and WardAgglomeration estimators would run
when given a data matrix with no samples, but they would produce a
meaningless clustering.
FIX Makefile to use Perl again

Still fails on Mac. But at least the xargs is gone.