Replaced Nokia copyrights

Replaced old Nokia copyrights with Digia copyrights.
Did NOT touch contact details, will change them later.
This change was made manually.

Change-Id: Ie0968b9913396761b1dc7ebabf38d9ec0c572f4d
Reviewed-by: Janne Anttila <janne.anttila@digia.com>
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>