message: Use new Tile::distanceTo method to reduce duplication
diff: @@ -189,10 +189,7 @@ bool validLanderSite(Tile* tile)
  return false;
  }
  - // bleh, direct copy from Tile::distanceTo()
  - int _x = tile->x() - ccLocationX();
  - int _y = tile->y() - ccLocationY();
  - float _dist = std::sqrt(static_cast<float>(_x * _x) + _y * _y);
  + auto _dist = tile->distanceTo(ccLocation());
  if (_dist > constants::LANDER_COM_RANGE)
  {
  doAlertMessage(constants::ALERT_LANDER_LOCATION, constants::ALERT_LANDER_COMM_RANGE);
  