WinRT: Disable QFileSystemWatcher

It might be possible to implement some kind of file system watcher using
http://msdn.microsoft.com/en-us/library/windows/apps/windows.storage.search.aspx

Change-Id: I375f299e2420f266c8e19d77360bdecf6ff88a56
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

src/corelib/global/qglobal.h

@@ -542,6 +542,7 @@ class QDataStream;
 
 #if defined(Q_OS_WINRT)
 #  define QT_NO_PROCESS
+#  define QT_NO_FILESYSTEMWATCHER
 #endif
 
 inline void qt_noop(void) {}