Cleanup code using forward declarations.

Use misc methods of avoiding unnecesary header includes.
Replace int typedefs with int##_t from stdint.h.
Replace PRI64[xdu] with PRI[xdu]64 from inttypes.h.
Normalize QT_VERSION ifs where possible.
Resolve some indirect dependencies as direct ones.
Remove extern declarations from .cpp files.

src/qt/notificator.cpp

@@ -4,27 +4,31 @@
 
 #include "notificator.h"
 
-#include <QApplication>
-#include <QMetaType>
-#include <QVariant>
-#include <QIcon>
-#include <QStyle>
-#include <QByteArray>
-#include <QSystemTrayIcon>
-#include <QMessageBox>
-#include <QTemporaryFile>
-#include <QImageWriter>
 
-#ifdef USE_DBUS
-#include <QtDBus>
-#include <stdint.h>
-#endif
+#include <QApplication>
+#include <QByteArray>
+#include <QIcon>
+#include <QImageWriter>
+#include <QMessageBox>
+#include <QMetaType>
+#include <QStyle>
+#include <QSystemTrayIcon>
+#include <QTemporaryFile>
+#include <QVariant>
 
 #ifdef Q_OS_MAC
-#include <ApplicationServices/ApplicationServices.h>
 #include "macnotificationhandler.h"
+
+#include <ApplicationServices/ApplicationServices.h>
 #endif
 
+#ifdef USE_DBUS
+#include <stdint.h>
+
+#include <QtDBus>
+#endif
+
+
 // https://wiki.ubuntu.com/NotificationDevelopmentGuidelines recommends at least 128
 const int FREEDESKTOP_NOTIFICATION_ICON_SIZE = 128;