Update copyright years

Author: Wuzzy2

README.md

@@ -116,7 +116,7 @@ distributed under the terms of the GNU General Public Licence version 2;
 images and sounds are distributed under the terms of the GNU Free Documentation
 Licence version 1.2. See the `COPYING` file for the full text of the licenses.
 
-Copyright 2004-2015 Andrey Korotaev <[email protected]> and others.
+Copyright 2004-2018 Andrey Korotaev <[email protected]> and others.
 See `QTfrontend/res/html/about.html` and `CREDITS` for a more complete list of
 authors.
 

man/hedgewars.6

@@ -42,7 +42,7 @@ If a CONNECTSTRING (e.g. "hwplay://netserver.hedgewars.org") is supplied, then h
 .
 .SH "COPYRIGHT"
 .
-Copyright \(co 2004\-2015 Andrey Korotaev, Igor Ulyanov
+Copyright \(co 2004\-2018 Andrey Korotaev, Igor Ulyanov
 .br 
 This is Free Software; this software is licensed under the GPL version 2, as published by the Free Software Foundation.
 There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

share/hedgewars/Data/Scripts/Multiplayer/Continental_supplies.lua

@@ -1,5 +1,7 @@
 --[[
-	Copyright (C) 2012 Vatten
+	=== Continental supplies ===
+	Created by Vatten in 2012.
+	Further worked on by the Hedgewars Team and contributors.
 
 	Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: