Update copyright notice from Swarming to LUCI; add AUTHORS and CONTRIBUTORS.

WATCHLISTS

-# Copyright (c) 2013 The Swarming Authors. All rights reserved.
+# Copyright (c) 2013 The LUCI Authors. All rights reserved.
 # Use of this source code is governed by the Apache v2.0 license that can be
 # found in the LICENSE file.
 
 # Watchlist Rules
 # Refer: http://dev.chromium.org/developers/contributing-code/watchlists
 
 {
 
   'WATCHLIST_DEFINITIONS': {
     'all': {
       'filepath': '.+',
     },
   },
 
   'WATCHLISTS': {
     'all': [
       # Add yourself here to get explicitly spammed.
     ],
   },
 
 }