Use C++ IO streams and qWarning() instead of (f)printf() for console IO.
Make user-visible strings translatable. Use invokeMethod() instead
of QTimer.
Fixes: QTBUG-111366
Pick-to: 6.5
Change-Id: I6990b964c2097267e04cd361b9cd8fc0a22a0135
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>