More informative and shorter headers.

nodes.lua

@@ -1,10 +1,8 @@
 --[[
-======================================================================
-This file is part of Map Tools.
+Map Tools: node definitions
 
 Copyright (c) 2012-2015 Calinou and contributors.
 Licensed under the zlib license. See LICENSE.md for more information.
-======================================================================
 --]]
 
 local S = maptools.intllib