(ctor) KillObjectiveInstance( KillObjective objective, MLQuestInstance instance )
      DataType ExtraDataType( get; )
      KillObjective Objective( get; set; )
      int Slain( get; set; )
      bool AddKill( Mobile mob, Type type )
      virtual bool IsCompleted()
      virtual void Serialize( GenericWriter writer )
      virtual void WriteToGump( Gump g, ref int y )