fix license text in COPYRIGHT.txt, remove duplicate Documentation/copyright.txt

Documentation/copyright.txt

-Here is the proposed copyright message to be added to all source files
-at their top.  There is one line that represents the main copyright holder.
-
-But in the future, the respective author of any newly coded module would be
-listed as the main copyright holder. Additional workers who might earn a
-partial copyright holder status of the respective module are simply left in the
-change_log.txt file, see the 2nd Copyright line below.
-
-
-/*
- * This program source code file is part of KICAD, a free EDA CAD application.
- *
- * Copyright (C) 1992-2010 <Creator>
- * Copyright (C) 1992-2010 Kicad Developers, see AUTHORS.txt for contributors.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, you may find one here:
- * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
- * or you may search the http://www.gnu.org website for the version 2 license,
- * or you may write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
- */

copyright.h

@@ -12,8 +12,8 @@ may choose to document this corresponding work in the CHANGELOG.txt file.
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2012 <author>
- * Copyright (C) 2012 KiCad Developers, see CHANGELOG.TXT for contributors.
+ * Copyright (C) 2013 <author>
+ * Copyright (C) 2013 KiCad Developers, see CHANGELOG.TXT for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License