code: public boolean isActive() {
      final Project project = getProject();
      if (!CUtil.isActive(project, this.ifProp, this.unlessProp)) {
        return false;
      }
      return true;
    }
docs: Determine if this def should be used.
  
  Definition will be active if the "if" variable (if specified) is set and
  the "unless" variable (if specified) is not set and that all reference
  or extended definitions are active
  
  @return true if processor is active