Qt copyrights are now in The Qt Company, so we could update the source
code headers accordingly. In the same go we should also fix the links to
point to qt.io.

Change-Id: Icc6f774c9ca37ea88ac024163386b16fc50fb2a7
Reviewed-by: Andras Becsi <andras.becsi@theqtcompany.com>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>