Removed Varible.var_type from base Orange.
Removed var_type from tests.
Removed use of var_type from widgets.
Tricked test_settings to work without VarTypes.
Fixed pull request.
Merge pull request #74 from markotoplak/master

remove var_type
Added ROC Analysis widget.
Added icon for 'ROC Analysis' widget.
Refactored 'ROC Analysis widget' code.
Display ROC Convex Hull.
Added docstrings.
Display iso-performance line.
Discrete color legend for continuous values
Nicer discrete color legend for scatter plot
PositionLegendItem remembers its last position for this widget
Nicer colors in scatter plot
Move expansion of probabilities to specialized sklearn Model/Fitter classes.
Remove VarTypes.
Moved dummies to tests.
Add naive bayes SQL test.