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

client/PRESUBMIT.py

-# Copyright 2012 The Swarming Authors. All rights reserved.
-# Use of this source code is governed under the Apache License, Version 2.0 that
-# can be found in the LICENSE file.
+# Copyright 2012 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 swarm_client.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into gcl.
 """
 
 def CommonChecks(input_api, output_api):
   import sys
   def join(*args):
@@ skipping 28 matching lines @@
 
   output.extend(
       input_api.canned_checks.RunUnitTestsInDirectory(
           input_api, output_api,
           input_api.os_path.join(input_api.PresubmitLocalPath(), 'tests'),
           whitelist=[r'.+_test\.py$'],
           blacklist=blacklist))
   return output
 
 
-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'All rights reserved\.\n'
-    r'.*? Use of this source code is governed under the Apache License, '
-      r'Version 2\.0 that\n'
-    r'.*? can be found in the LICENSE file\.(?: \*/)?\n'
-  ) % {
-    'year': years_re,
-  }
-  return license_header
-
-
 def CheckChangeOnUpload(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
 def CheckChangeOnCommit(input_api, output_api):
-  output = CommonChecks(input_api, output_api)
-  output.extend(input_api.canned_checks.PanProjectChecks(
-      input_api, output_api,
-      owners_check=False,
-      license_header=header(input_api)))
-  return output
+  return CommonChecks(input_api, output_api)