/// <summary>
 /// Saves the passed in world info.
 /// </summary>
 public virtual void SaveWorldInfo(WorldInfo worldinfo)
 {
 }
 /// <summary>
 /// saves level.dat and backs up the existing one to level.dat_old
 /// </summary>
 public virtual void SaveWorldInfoAndPlayer(WorldInfo worldinfo, List <EntityPlayer> list)
 {
 }