Fix QTKit Video Playback on QT 4.8 RC

QT-BUG 22574 suggests there is a problem with the
QMacCocoaContainer on 4.8 RC 0. This is a quick workaround
for those building against the 4.8 release candidate.

src/QtMacVideoWindow.mm

@@ -193,6 +193,10 @@ MediaHelper::listMedia(QDir dir)
 
 QtMacMovieView::QtMacMovieView (QWidget *parent) : QMacCocoaViewContainer (0, parent)
 {
+#if QT_VERSION >= 0x040800 // see QT-BUG 22574, QMacCocoaContainer on 4.8 is "broken"
+    setAttribute(Qt::WA_NativeWindow);
+#endif
+
     NSRect frame;
     // allocate the player
     player = [[QTMovieView alloc] initWithFrame:frame];