ENH : simplify ProabilisticPCA covariance_ computation + misc in pca.py
ENH : avoid extra alloc in _infer_dimension_ in pca.py
FIX : self.component in PCA was changed by fit when passed mle or explained variance
ENH : avoid extra allocation in FactorAnalysis
ENH : use math.log and not np.log for scalars
doc fix
misc
FIX : broken fit_transform
Merge pull request #2338 from agramfort/pca_cleanup

PCA cleanup