add GPLv3+ header to all lua scripts

mods/ra/maps/soviet-02b/soviet02b.lua

@@ -1,3 +1,11 @@
+--[[
+   Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
+   This file is part of OpenRA, which is free software. It is made
+   available to you 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. For more
+   information, see COPYING.
+]]
 IntroAttackers = { IntroSoldier1, IntroSoldier2, IntroSoldier3 }
 
 BridgeShroudTrigger = { CPos.New(63, 71), CPos.New(64, 71), CPos.New(65, 71), CPos.New(69, 65), CPos.New(70, 65), CPos.New(71, 65) }