Fix BlackGui header includes

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

refs #598

src/blackgui/components/dbdistributorcomponent.h

@@ -13,12 +13,16 @@
 #define BLACKGUI_COMPONENTS_DBDISTRIBUTORCOMPONENT_H
 
 #include "blackgui/blackguiexport.h"
-#include "blackgui/enableforviewbasedindicator.h"
 #include "blackgui/components/enablefordockwidgetinfoarea.h"
+#include "blackgui/enableforviewbasedindicator.h"
 #include "blackmisc/network/entityflags.h"
+
 #include <QFrame>
+#include <QObject>
 #include <QScopedPointer>
 
+class QWidget;
+
 namespace Ui { class CDbDistributorComponent; }
 
 namespace BlackGui