build: fix copyright date in old files.

caca/attr.c

@@ -1,6 +1,6 @@
 /*
  *  libcaca       Colour ASCII-Art library
- *  Copyright (c) 2002-2010 Sam Hocevar <sam@hocevar.net>
+ *  Copyright (c) 2002-2012 Sam Hocevar <sam@hocevar.net>
  *                All Rights Reserved
  *
  *  This library is free software. It comes without any warranty, to

ruby/caca-canvas.c

@@ -1,6 +1,6 @@
 /*
  *  libcaca Ruby bindings
- *  Copyright (c) 2007-2010 Pascal Terjan <pterjan@linuxfr.org>
+ *  Copyright (c) 2007-2012 Pascal Terjan <pterjan@linuxfr.org>
  *
  *  This library is free software. It comes without any warranty, to
  *  the extent permitted by applicable law. You can redistribute it

ruby/caca-dither.c

@@ -1,6 +1,6 @@
 /*
  *  libcaca Ruby bindings
- *  Copyright (c) 2007-2010 Pascal Terjan <pterjan@linuxfr.org>
+ *  Copyright (c) 2007-2012 Pascal Terjan <pterjan@linuxfr.org>
  *
  *  This library is free software. It comes without any warranty, to
  *  the extent permitted by applicable law. You can redistribute it

ruby/caca-font.c

@@ -1,6 +1,6 @@
 /*
  *  libcaca Ruby bindings
- *  Copyright (c) 2007-2010 Pascal Terjan <pterjan@linuxfr.org>
+ *  Copyright (c) 2007-2012 Pascal Terjan <pterjan@linuxfr.org>
  *
  *  This library is free software. It comes without any warranty, to
  *  the extent permitted by applicable law. You can redistribute it