Fix BlackCore header includes

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

refs #598

src/blackcore/contextownaircraftproxy.cpp

@@ -8,9 +8,13 @@
  */
 
 #include "blackcore/contextownaircraftproxy.h"
-#include <QObject>
-#include <QMetaEnum>
+#include "blackmisc/dbus.h"
+#include "blackmisc/genericdbusinterface.h"
+
 #include <QDBusConnection>
+#include <QLatin1Literal>
+#include <QObject>
+#include <QtGlobal>
 
 using namespace BlackMisc;
 using namespace BlackMisc::Aviation;