src/gpl-3-0.[ch]: New files

mq_gpl_3_0_html() builds a long string from an array of shorter strings.
This works around possibly limited literal string lengths of compilers,
as described by this warning from GCC:

    $ make
    [...]
      CC       src/about/marquee-version.o
    src/about/version.c:726:2: warning: string length ‘36973’ is greater than the length ‘4095’ ISO C99 compilers are required to support [-Woverlength-strings]
      ;
      ^
    [...]

1 files changed, 30 insertions, 0 deletions

diff --git a/src/gpl-3-0.h b/src/gpl-3-0.h
new file mode 100644
index 0000000..c28c9f2
--- /dev/null
+++ b/src/gpl-3-0.h
@@ -0,0 +1,30 @@
+/*
+ * GNU GPL version 3.0 license text
+ *
+ * Copyright (C) 2017  Patrick McDermott
+ *
+ * This file is part of Marquee.
+ *
+ * Marquee 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) any later version.
+ *
+ * Marquee 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 Marquee.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MQ_GPL_3_0_H
+#define MQ_GPL_3_0_H
+
+#include <glib.h>
+
+const gchar *
+mq_gpl_3_0_html(void);
+
+#endif