QtIFW

Make sure we remove all directories we created, nothing more.

Special case on windows, if we created a folder inside the start
menu, try as long as we fail to remove all empty directories.

Change-Id: Idf67a43cbbcfc44746438c523a63def0e07e7de9
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>