QMdi: Don't emit subWindowActivated during StyleChange handling.

The handling of StyleChange de-maximizes the child window temporarily,
which was emitting subWindowActivated.
This would crash lokalize, because deactivating a window means deleting
the widgets associated with it, and style-change handling is done in
QApplication by looping over QApplication::allWidgets, which would then
contain dangling pointers.

Full valgrind log at https://bugs.kde.org/show_bug.cgi?id=271494#c7

Change-Id: I256da214bf00fd7925dcee67b4f0414e57fc453b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
(cherry picked from qtbase/a6e5ccbe223c5a606e15556e8708e863442d9f72)
Windows: Fix one of the two file dialog bottlenecks.

This patch reduces the number of calls to GetFileAttributesEx()
when icon lookup is being done.

The second bottleneck is a couple of isSymLink() calls. Will fix
that next.

Task-number: QTBUG-13182
(cherry picked from commit a7f6f32fadd5024697c16dfcbc07d6d11beb45fa)

Change-Id: If42b791d22fe0429a3b43992bad037afad09c448
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Windows: Fix the last file dialog bottleneck.

Went from taking 30 seconds to 2 seconds, on a SDCard with 10k files.

Windows file dialog does not resolve NTFS symlinks,
it just shows an empty icon, and the link name, not the target.

This allows for a big performance gain by reducing the number of
calls to GetFileAttributesEx() by checking the extension directly.

This also fixes the problems with the native file dialog, which
for some reason, is creating a QFileSystemModel too.

Task-number: QTBUG-13182
(cherry picked from commit 51f00deffac49c4277425837f0132b0c721bb689)

Change-Id: If7bd63d68e1870c5e48907ae79f4c4bdc6972b00
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Fixed some declarative auto tests

This is a backport from qt5/qtquick1 (commit aad8f0b)

Change-Id: Ia3eacce5ccd50827526203a9992ddef81a9f0c41
Reviewed-by: Alan Alpert <aalpert@blackberry.com>