Several files in Toolbox/UKF have the  copyright

Several files in Toolbox/UKF have the following copyright

```
% Copyright (C) 2002 Simo Särkkä
%
% $Id: gauss_pdf.m 111 2007-09-04 12:09:23Z ssarkka $
%
% This software is distributed under the GNU General Public 
% Licence (version 2 or later); please refer to the file 
% Licence.txt, included with the software, for details.
```