Added entry for slicot in license file

license.txt

@@ -322,3 +322,20 @@ License: GPL-3+
  You should have received a copy of the GNU General Public License
  along with this program.  If not, see
  <http://www.gnu.org/licenses/>.
+
+Files: mex/sources/libslicot/*
+Copyright: 2002-2009, NICONET e.V.
+License: GPL-2+
+ This program is free software: you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation, either version 2 of
+ the License, or (at your option) any later version.
+ .
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+ .
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see
+ <http://www.gnu.org/licenses/>.