Add missing license text

LICENSES/LicenseRef-KDE-Accepted-GPL.txt

@@ -0,0 +1,12 @@
+This library 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 3 of
+the license or (at your option) at any later version that is
+accepted by the membership of KDE e.V. (or its successor
+approved by the membership of KDE e.V.), which shall act as a
+proxy as defined in Section 14 of version 3 of the license.
+
+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.