TST skip SparsePCA n_jobs!=1 test on Mac OS X because it hangs
adding test for csr data for partial fit
pep8-ing
PY3 file handling
BUG restore joblib logging behavior

.write is not the same as print: the former doesn't append a '\n'.
BUG joblib writes to wrong dir

Sorry, I should have reviewed #2978 more carefully.
DOC trees/ensembles: class labels need not be integers
Add space to be consistent with _tree.pyx
DOC document internal tree class
ENH rename CONSTANT_FEATURE_THRESHOLD to FEATURE_THRESHOLD + revert some pep8 fix for readability
DOC missing words
Merge pull request #2977 from arjoly/tree-cleanup

[MRG] Some cleanup in _tree.pyx
removing copy() and adding tests for multiple forms of sparse matrices
removing tests for multiple sparse matrix formats
DOC: wordings
Preserve CSR storage format when input is CSR in sparse_center_data
Merge pull request #2991 from Manoj-Kumar-S/csr_sparse_center

Preserve CSR storage format when input is CSR in sparse_center_data
Cosmit
MAINT: point out HMMLearn

New repository for the HMM code
Merge pull request #2955 from larsmans/less-blas

[MRG+1] use CBLAS instead of Fortran BLAS in Liblinear