Print GPL license notice and SEGA disclaimer in console on start

src/d_main.c

@@ -927,6 +927,20 @@ void D_SRB2Main(void)
 	INT32 pstartmap = 1;
 	boolean autostart = false;
 
+	// Print GPL notice for our console users (Linux)
+	CONS_Printf(
+	"\n\nSonic Robo Blast 2\n"
+	"Copyright (C) 1998-2018 by Sonic Team Junior\n\n"
+    "This program comes with ABSOLUTELY NO WARRANTY.\n\n"
+    "This is free software, and you are welcome to redistribute it\n"
+    "and/or modify it under the terms of the GNU General Public License\n"
+	"as published by the Free Software Foundation; either version 2 of\n"
+	"the License, or (at your option) any later version.\n"
+	"See the 'LICENSE.txt' file for details.\n\n"
+	"Sonic the Hedgehog and related characters are trademarks of SEGA.\n"
+	"We do not claim ownership of SEGA's intellectual property used\n"
+	"in this program.\n\n");
+
 	// keep error messages until the final flush(stderr)
 #if !defined (PC_DOS) && !defined (_WIN32_WCE) && !defined(NOTERMIOS)
 	if (setvbuf(stderr, NULL, _IOFBF, 1000))