there was no bug before but an obscure img_to_graph(mask, mask)
that is now replaced by grid_to_graph (makes a connectivity structure
for a grid of pixels/voxels)
- pipeline and GridSearchCV have been cleaned
- feat agglo inherits from TransformerMixin
- s / n_comp / n_components in hierarchical.py
Conflicts:
scikits/learn/feature_selection/univariate_selection.py
scikits/learn/pipeline.py
scikits/learn/tests/test_pipeline.py