public void RemoveFieldObject(FieldObject removingObject)
{
objects.Remove (removingObject);
objectsOnField [removingObject.x] [removingObject.y].Remove (removingObject);
}
public void AddFieldObject(FieldObject newObject)
{
objects.Add (newObject);
objectsOnField [newObject.x] [newObject.y].Add (newObject);
}