add missing copyright headers

errors.go

@@ -1,3 +1,8 @@
+// Copyright 2014 The Go Authors.
+// See https://code.google.com/p/go/source/browse/CONTRIBUTORS
+// Licensed under the same terms as Go itself:
+// https://code.google.com/p/go/source/browse/LICENSE
+
 package http2
 
 import "fmt"

frame.go

@@ -1,3 +1,8 @@
+// Copyright 2014 The Go Authors.
+// See https://code.google.com/p/go/source/browse/CONTRIBUTORS
+// Licensed under the same terms as Go itself:
+// https://code.google.com/p/go/source/browse/LICENSE
+
 package http2
 
 import (

h2server/h2server.go

@@ -1,3 +1,8 @@
+// Copyright 2014 The Go Authors.
+// See https://code.google.com/p/go/source/browse/CONTRIBUTORS
+// Licensed under the same terms as Go itself:
+// https://code.google.com/p/go/source/browse/LICENSE
+
 package main
 
 import (

http2.go

@@ -1,3 +1,8 @@
+// Copyright 2014 The Go Authors.
+// See https://code.google.com/p/go/source/browse/CONTRIBUTORS
+// Licensed under the same terms as Go itself:
+// https://code.google.com/p/go/source/browse/LICENSE
+
 // Package http2 implements the HTTP/2 protocol.
 //
 // It currently targets draft-13. See http://http2.github.io/