Fix BlackGui header includes

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

refs #598

src/blackgui/components/internalscomponent.h

@@ -14,8 +14,12 @@
 
 #include "blackgui/blackguiexport.h"
 #include "blackmisc/aviation/aircraftparts.h"
+
+#include <QObject>
+#include <QScopedPointer>
 #include <QWidget>
-#include <QScopedArrayPointer>
+
+class QShowEvent;
 
 namespace Ui { class CInternalsComponent; }