goprotobuf: Use a standard redirecting AUTHORS and CONTRIBUTORS file.

Correct copyright notice to "The Go Authors" throughout.

R=rsc, bradfitz
CC=golang-dev
http://codereview.appspot.com/6845101
diff --git a/proto/text_parser.go b/proto/text_parser.go
index 1f170bf..3c79876 100644
--- a/proto/text_parser.go
+++ b/proto/text_parser.go
@@ -1,6 +1,6 @@
 // Go support for Protocol Buffers - Google's data interchange format
 //
-// Copyright 2010 Google Inc.  All rights reserved.
+// Copyright 2010 The Go Authors.  All rights reserved.
 // http://code.google.com/p/goprotobuf/
 //
 // Redistribution and use in source and binary forms, with or without