QtIFW

Cleanup.

Iterate just once and remove all tags from existing xml.
Throw and print error if we can't open an supported archive.
Refactor duplicated copy code - license,translation,ui files.

Change-Id: I60e215fdc5591ff9dcb5509db74448298ec6b752
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>