Convert remaining license headers to SPDX

src/backends/maxima/maximasession.h

 /*
-    Tims 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, write to the Free Software
-    Foundation, Inc., 51 Franklin Street, Fifth Floor,
-    Boston, MA  02110-1301, USA.
+    SPDX-License-Identifier: GPL-2.0-or-later
     SPDX-FileCopyrightText: 2009-2012 Alexander Rieder <alexanderrieder@gmail.com>
 */
 

src/backends/sage/sagesession.h

 /*
-    Tims 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, write to the Free Software
-    Foundation, Inc., 51 Franklin Street, Fifth Floor,
-    Boston, MA  02110-1301, USA.
+    SPDX-License-Identifier: GPL-2.0-or-later
     SPDX-FileCopyrightText: 2009 Alexander Rieder <alexanderrieder@gmail.com>
 */
 

src/main.cpp

@@ -65,7 +65,7 @@ int main(int argc, char **argv)
                      QLatin1String(CANTOR_VERSION),
                      i18n(description),
                      KAboutLicense::GPL,
-                     i18n("(C) 2016 Filipe Saraiva<br/>SPDX-FileCopyrightText: 2009-2015 Alexander Rieder "),
+                     i18n("(C) 2016 Filipe Saraiva<br/>(C) 2009-2015 Alexander Rieder"),
                      QString(),
                      QLatin1String("https://cantor.kde.org/"));