DefaultUnDo 0.3.0
added ValueUnDo.MergeInterval property
added ValueUnDo.MergeDescriptionAction property
added GroupUnDo.MergeDescriptionAction property
removed description comparison for merge in GroupUnDo and ValueUnDo
added ValueUnDo.MergeInterval property
added ValueUnDo.MergeDescriptionAction property
added GroupUnDo.MergeDescriptionAction property
removed description comparison for merge in GroupUnDo and ValueUnDo