Add license header to all files

stm-firmware/include/helper-macros/helper-macros.h

@@ -1,3 +1,23 @@
+/* Reflow Oven Controller
+ *
+ * Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
+ *
+ * This file is part of the Reflow Oven Controller Project.
+ *
+ * The reflow oven controller is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * GDSII-Converter 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 the reflow oven controller project.
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #ifndef __HELPER_MACROS_H__
 #define __HELPER_MACROS_H__