message: Write meta data for MineFacility
diff: @@ -469,6 +469,20 @@ void StructureManager::serialize(NAS2D::Xml::XmlElement* element)
  structureElement->linkEndChild(waste);
  }
  + if (structure->isMineFacility())
  + {
  + MineFacility* facility = static_cast<MineFacility*>(structure);
  +
  + auto* trucks = new NAS2D::Xml::XmlElement("trucks");
  + trucks->attribute("assigned", facility->assignedTrucks());
  +
  + auto* extension = new NAS2D::Xml::XmlElement("extension");
  + extension->attribute("turns_remaining", facility->digTimeRemaining());
  +
  + structureElement->linkEndChild(trucks);
  + structureElement->linkEndChild(extension);
  + }
  +
  structures->linkEndChild(structureElement);
  }
  