Clarify licenses

- add license headers to everything
- convert a few files from public domain or LGPL2.1+ to GPL2+
- some archaeology to clarify which files are from which library

1 files changed, 5 insertions, 18 deletions

diff --git a/src/ui/monitor.cpp b/src/ui/monitor.cpp
index af14d797d..1a15c015e 100644
--- a/src/ui/monitor.cpp
+++ b/src/ui/monitor.cpp
@@ -1,26 +1,13 @@
-/**
- * \file
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
  * \brief helper functions for retrieving monitor geometry, etc.
  *//*
  * Authors:
+ * see git history
  *   Eduard Braun <eduard.braun2@gmx.de>
  *
- * Copyright 2018 Authors
- *
- * This file is part of Inkscape.
- *
- * Inkscape 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.
- *
- * Inkscape 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 Inkscape.  If not, see <http://www.gnu.org/licenses/>.
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
  */
 
 #include <gdkmm/rectangle.h>