Got rid of kappa import and added our own implementation
Switched to using sklearn 0.14's make_scorer method for handling scoring metrics, and cleaned up metric code considerably. Removed dependency on ml_metrics package, and added support for all sklearn metrics for tuning.
Fixed typo in registering linear_weighted_kappa and updated documentation.
Fixed references to accuracy function in test_skll.py
Refactored kappa unit tests a bit to help pinpoint problem.
Fixed an issue with kappa unit tests.
Removed fixed standard scaler, because we're requiring sklearn 0.14+ now. Also fixed typo with name of scoring argument for GridSearchCV
Fixed kappa calculation so that it passes unit tests. Mostly by making the code more similar to yorchopolis's.
Fixed issue where weighting scheme was getting overwritten in skll.metrics.kappa. Completed last bit of refactoring to make grid_objective work in it's new string form.
Cleaned up sklearn.metrics imports.
Updated documentation to reflect newly supported metrics. Also updated changelog in readme.
Merge pull request #18 from EducationalTestingService/refactor_metrics

Switched to using scikit-learn 0.14's method for handling scoring functions.