ENH : make PCA scoring work with n_features is big. Avoid covariance computation in PCA.fit
DOC : remove reference to ProbabilisticPCA in doc
update what's new
FIX : do not store precision_ attribute in score method
ENH : add get_precision method with matrix inversion lemma  to PCA for faster scoring
ENH : add tests for get_precision in PCA + some fixes for corner cases
ENH : add get_precision method with matrix inverse lemma  to FactorAnalysis + use precision in score
pep8
ENH : add PCA+FA model selection example