[5017] Copyright years updated.

src/bin/dhcp4/dhcp4_lexer.ll

@@ -1,4 +1,4 @@
-/* Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+/* Copyright (C) 2016 Internet Systems Consortium, Inc. ("ISC")
 
    This Source Code Form is subject to the terms of the Mozilla Public
    License, v. 2.0. If a copy of the MPL was not distributed with this

src/bin/dhcp4/dhcp4_parser.yy

@@ -1,4 +1,4 @@
-/* Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+/* Copyright (C) 2016 Internet Systems Consortium, Inc. ("ISC")
 
    This Source Code Form is subject to the terms of the Mozilla Public
    License, v. 2.0. If a copy of the MPL was not distributed with this

src/bin/dhcp6/dhcp6_lexer.ll

@@ -1,4 +1,4 @@
-/* Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+/* Copyright (C) 2016 Internet Systems Consortium, Inc. ("ISC")
 
    This Source Code Form is subject to the terms of the Mozilla Public
    License, v. 2.0. If a copy of the MPL was not distributed with this

src/bin/dhcp6/dhcp6_parser.yy

@@ -1,4 +1,4 @@
-/* Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+/* Copyright (C) 2016 Internet Systems Consortium, Inc. ("ISC")
 
    This Source Code Form is subject to the terms of the Mozilla Public
    License, v. 2.0. If a copy of the MPL was not distributed with this