infoviewer: use forward declaration instead of including infoviewer_bb

src/gui/infoviewer.cpp

@@ -36,6 +36,7 @@
 #include <config.h>
 #endif
 #include "infoviewer.h"
+#include "infoviewer_bb.h"
 
 #include <algorithm>
 

src/gui/infoviewer.h

@@ -41,11 +41,11 @@
 #include <driver/fade.h>
 #include <system/settings.h>
 #include "widget/menue.h"
-#include <gui/infoviewer_bb.h>
 #include <string>
 #include <zapit/channel.h>
 #include <gui/components/cc.h>
 
+class CInfoViewerBB;
 class CInfoViewer
 {
  private: