Fix BlackCore header includes

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

refs #598

src/blackcore/voicechannel.h

@@ -16,11 +16,10 @@
 #include "blackmisc/statusmessage.h"
 #include "blackmisc/audio/voiceroomlist.h"
 #include "blackmisc/aviation/callsignset.h"
+
 #include <QObject>
 #include <QScopedPointer>
 
-//! \file
-
 namespace BlackCore
 {
     //! Interface to a voice channel