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/protoc-gen-go/generator/generator.go b/protoc-gen-go/generator/generator.go
index 7bf7b39..ce90a15 100644
--- a/protoc-gen-go/generator/generator.go
+++ b/protoc-gen-go/generator/generator.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