FIX TfidfVectorizer to no longer ignore binary param

Also changed the docs to clarify that binary=True means
binary tf, not binary output.
DOC: add OkCupid testimonial
Merge pull request #2997 from GaelVaroquaux/okcupid_testimonial

DOC: add OkCupid testimonial
Merge pull request #2982 from kmike/fix-macos-hangs

[MRG+1] MacOS X testing improvements
adding test for csc and csr sparse matrix
DOC use hyperlink colour when in tt
Merge pull request #3003 from jnothman/hyperlinked_tt_colour

DOC use hyperlink colour when in tt
adding change to whats_new
FIX: more robust skip of implicit constructor

Parameter introspection requires introspecting the keyword arguments of the
constructor of Python classes deriving from BaseEstimator.

This can be problematic for classes that do not override the default
constructor. Introspecting the implicit constructor used to raise a TypeError
but this is no longer the case in Python 3.4+. Hence with use a explicit check
for the implicit constructor prior to using inspection.
Merge conflict in whats_new.rst
Merge pull request #3006 from ogrisel/fix-implicit-init-introspection

[MRG] FIX: more robust skip of implicit constructor
MAINT don't use Perl in Makefile when sed suffices

Also replaced xargs with find's own command execution. This is more
robust in the face of paths with whitespace in them.
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