fix: warm_start demo in narrative documentation
updated whats new
ENH speed up SVMlight loader using Cython's array support

Loading the binary covtype dataset from
http://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html
now takes 1/3 less wall clock time, which includes disk I/O and
decompression (bzip2).

Got rid of ArrayBuilder in the process.
cosmit
FIX remove ``.description`` from test generators as this is not thread-safe.
ENH Define fused types so only two functions are generated.
malloc / realloc checks
correct rc values
Merge pull request #2719 from amueller/remove_description_in_common_tests

FIX remove ``.description`` from test generators
cosmit: better errors
do not alter n_estimators after early stopping
Merge pull request #2720 from amueller/chi2_fused_types

MRG define fused types in chi2 for less code
Pre-initialize all trees before dispatching
Merge pull request #2724 from glouppe/forest-2721

[FIX] Pre-initialize all trees before dispatching
FIX Use Py2.6-compatible string formatting

Also PEP8
ENH: make forests' test_parallel_train run faster
Merge branch 'master' into DOC_olivier_tut
WEBSITE FIX spotify logo!
Typo in examples

Fixes #2725
FIX: np.searchsorted numpy bug on unicode objects also impacts 1.6.1
cosmit: better exception
remove troublesome 32bit test