message: Use dictionaryToAttributes for mine trucks and extension
diff: @@ -105,14 +105,18 @@ namespace
  {
  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);
  + structureElement->linkEndChild(
  + NAS2D::dictionaryToAttributes(
  + "trucks",
  + {{{"assigned", facility->assignedTrucks()}}}
  + )
  + );
  + structureElement->linkEndChild(
  + NAS2D::dictionaryToAttributes(
  + "extension",
  + {{{"turns_remaining", facility->digTimeRemaining()}}}
  + )
  + );
  }
  if (structure->structureClass() == Structure::StructureClass::Maintenance)
  