Refactor loss_func and score_func warnings in grid_search
Add score_overrides_loss to _deprecate_loss_and_score_funcs
Add deprecation warnings in Ridge
Add deprecation warnings in rfe
Add catching of the deprecation warnings in rfe and ridge tests
Refactor loss_func and score_func warnings in cross_validation + replacement in two examples
Fix 'scoring' docstrings
Imp documentation
Fix tests
Fix grid_search.py example