Update license headers for plugins and includes.

plugins/include/message_stocks.inc

@@ -1,10 +1,15 @@
-/* Message Stocks
-*
-* by the AMX Mod X Development Team
-*
-* This file is provided as is (no warranties).
-*
-*/
+// vim: set ts=4 sw=4 tw=99 noet:
+//
+// AMX Mod X, based on AMX Mod by Aleksander Naszko ("OLO").
+// Copyright (C) The AMX Mod X Development Team.
+//
+// This software is licensed under the GNU General Public License, version 3 or higher.
+// Additional exceptions apply. For full license details, see LICENSE.txt or visit:
+//     https://alliedmods.net/amxmodx-license
+
+//
+// Message Stocks
+//
  
 #if defined _message_stocks_included
 	#endinput