Update copyright year

Update the copyright notice with the current year, 2013.

Signed-off-by: Marcus Karlsson <mk@acc.umu.se>
Add an explicit copyright notice to the directory

The copyright notice is only included in the program file itself. Add a
notice to the top level directory called COPYING, which covers the
entire repository and puts it in a recognizable place.

Signed-off-by: Marcus Karlsson <mk@acc.umu.se>