Fix BlackGui header includes

* Include only what is used
* Use forward declaration when possible
* Sorted includes

refs #598

src/blackgui/models/atcstationlistmodel.h

@@ -13,10 +13,13 @@
 #define BLACKGUI_ATCLISTMODEL_H
 
 #include "blackgui/blackguiexport.h"
-#include "blackmisc/aviation/atcstationlist.h"
 #include "blackgui/models/listmodelbase.h"
-#include <QAbstractItemModel>
-#include <QStandardItemModel>
+#include "blackmisc/aviation/atcstation.h"
+#include "blackmisc/aviation/atcstationlist.h"
+
+#include <QObject>
+
+class QStandardItemModel;
 
 namespace BlackGui
 {