Added create_feature_vectors and unittest.
Updated to use FV and use KNN instead of QDA for classification.
Added select_classes + tests
Added remove_classes + tests.
Fixed docstrings for select_epochs
Fixed meth and func confusion in sphinx docs.
Updated examples to use select_classes
Added signed_r_square + tests
Polished docs with shortened references to Data and Data.copy.
Removed some unused extensions.