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

PRESUBMIT.py

-# Copyright 2013 The Swarming Authors. All rights reserved.
+# Copyright 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.
 
-"""Top-level presubmit script for swarming.
+"""Top-level presubmit script for LUCI.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into gcl.
 """
 
 
 def header(input_api):
   """Returns the expected license header regexp for this project."""
   current_year = int(input_api.time.strftime('%Y'))
   allowed_years = (str(s) for s in reversed(xrange(2011, current_year + 1)))
   years_re = '(' + '|'.join(allowed_years) + ')'
   license_header = (
-    r'.*? Copyright %(year)s The Swarming Authors\. '
+    r'.*? Copyright %(year)s The LUCI Authors\. '
       r'All rights reserved\.\n'
     r'.*? Use of this source code is governed by the Apache v2\.0 license '
       r'that can be\n'
     r'.*? found in the LICENSE file\.(?: \*/)?\n'
   ) % {
     'year': years_re,
   }
   return license_header
 
 
@@ skipping 10 matching lines @@
       owners_check=False,
       license_header=header(input_api))
 
 
 def CheckChangeOnUpload(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
 def CheckChangeOnCommit(input_api, output_api):
   return CommonChecks(input_api, output_api)