[MRG] Remove deprecated parameters whose removal was scheduled for 0.15

Some deprecated parameters were scheduled for removal for 0.15 but managed to escape it. 

The one with most impact was score_func and loss_func from sklearn.metrics.scorer.check_scoring, which was still used in quite a few different places, e.g. cross_validation.py, grid_search.py, a few different tests, ...
Do we still need these local variables?