BUG: ValueError was assigned as local variable!
COSMIT: no need for parentheses.
More robust unit tests for fast_dot.
Remove warnings in ProbabilisticPCA tests.
One less warning in QDA tests.
Simplify fast_dot.
DOC explanatory sentence for svm grid search example
Merge pull request #2583 from amueller/doc_rbf_parameters

MRG DOC explanatory sentence for svm grid search example
Remove print statement.
Add lobpcg in possible solvers.
Fix fragile symmetry check.
Fix fragile test.

Failed on two of my machines.
Fix typo in test.
DOC remove confusing comment from TruncatedSVD

The comment was supposed to suggest that there might be a faster
way to do fit_transform than the matrix-vector multiplication
that it currently performs, but the suggested alternative actually
has higher complexity.
ENH: add PolynomialFeatures preprocessor
FIX: errors in kernel parameters for OneClassSVM
address PR2585 comments
import pylab -> import matplotlib.pyplot
TST: fix PolynomialFeatures test error
TST: fix doctests & pep8