v2.1.21: Survival rules fixes

• Bugfix in parsing expert survival rules when survival status attribute is nominal.
• Ugly consequence of survival rules (survival_status = {NaN}) not printed in log nor needed in the expert knowledge.

v2.1.20: Several fixes

• Nominal attribute values not present in the data not considered in the induction.
• Trimming tokens from arff file metadata before parsing.
• Contrast set fix: group labels written in the log instead of numerical identifiers.

v1.7.21: Contrast set fix

Contrast group labels written in the log instead of numerical identifiers.

v1.7.20: Condition ordering fix

Conditions printed in the order they had been added to the rule.

v2.1.18b: Tests updated

Test results updated to follow different condition ordering.

v2.1.18: Condition ordering fix

Conditions printed in the order they had been added to the rule.

v2.1.16: Columns with missing values in the first row properly parsed

version bump

v2.1.15: First public RuleKit 2 release

Removed RapidMiner dependency

v1.7.19: Contrast sets induction working properly again

Some logging added during contrast sets induction.

v1.7.14: Added `mincov_new` adjustment at the end of growing (results may change).

Added mincov_new adjustment at the end of growing. Small fixes making the algorithm insensitive to the value ordering of nominal attributes.