Fix crash when accessing QFileDialog::selectedFiles() before widgets exist.

Discovered while investigating:

Task-number: QTBUG-38414
Change-Id: I764195254ba4b54c86079c6e8ef750d6249960d9
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Update AddressBook Example

Adding parent to QDialog
As proposed on qt-project.org forum:
http://qt-project.org/forums/viewthread/41686/

Change-Id: Ib66d24e4afd0be803a1080c37bc6c0a189844786
Reviewed-by: Sze Howe Koh <szehowe.koh@gmail.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Fix QFileDialog::viewMode() when using a native file dialog.

It should return the view mode that was set in setViewMode() and
stored in the options.

Change-Id: Iaaa94a201a25baa251446688bf5bdaca5cf3373b
Reviewed-by: Mark Gaiser
Reviewed-by: Dominik Haumann <dhaumann@kde.org>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>