Sort by predicted values in Predictions widget
TestLearners AUC metric.
Restore original order in Predictions widget.
Clean imports.
Hides sort indicator for unsorted ordering in Predictions widget.
Improve code clarity.
Merge pull request #179 from thocevar/predictions

Sort by predicted values in Predictions widget
Binary measures.
Merge pull request #182 from acopar/test-learners-auc

Test learners auc
Supported numpy arrays as inputs for distances. Handling e1, e2 separately. Implemented extension ob basic classes.
Added documentation for Distances.
Merge pull request #181 from nikicc/npmat

Supported numpy arrays as inputs for distances.
Documentation and small fixes for Domain