COPYING: Update copyrights

I went through all of the protocols and used the copyright hints in
them and used the result of that to put in the COPYING file. One
exception was the fullscreen shell which was missing the copyright
details. As per direct contact with the original author, copyright of
fullscreen shell should be attributed to the author himself and was
therefore added to COPYING.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>

COPYING

@@ -1,7 +1,11 @@
-Copyright © 2008-2012 Kristian Høgsberg
-Copyright © 2010-2012 Intel Corporation
-Copyright © 2011 Benjamin Franzke
-Copyright © 2012 Collabora, Ltd.
+Copyright © 2008-2013 Kristian Høgsberg
+Copyright © 2010-2013 Intel Corporation
+Copyright © 2013      Rafael Antognolli
+Copyright © 2013      Jasper St. Pierre
+Copyright © 2014      Jonas Ådahl
+Copyright © 2014      Jason Ekstrand
+Copyright © 2014-2015 Collabora, Ltd.
+Copyright © 2015      Red Hat Inc.
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the "Software"),