Add missing GPL headers, and copyright claims that certainly apply.

* Fix (a subset of)? files with non-trivial code that are missing GPL headers.

* A few copyright claims added which I am certain apply, but which I had
  missed out on the original commits.

NB: Copyright claims are not exclusive and the addition of any copyright
claim should not be read as implying a lack of any further claims, or
denying the validity of any other claims.  All those with claims of
copyright over any portion of Quagga are welcome to submit them, ideally as
patches to update copyright strings in files.
diff --git a/tests/bgp_capability_test.c b/tests/bgp_capability_test.c
index 65c6a70..96f18f0 100644
--- a/tests/bgp_capability_test.c
+++ b/tests/bgp_capability_test.c
@@ -1,3 +1,24 @@
+/* 
+ * Copyright (C) 2007 Sun Microsystems, Inc.
+ *
+ * This file is part of Quagga.
+ *
+ * Quagga 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, or (at your option) any
+ * later version.
+ *
+ * Quagga 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 Quagga; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.  
+ */
+
 #include <zebra.h>
 
 #include "vty.h"