netchan: move to old/netchan

Part of Go version 1 rearrangement.
No gofix, since the new name is not in Go 1.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5245055

src/pkg/Makefile

@@ -130,7 +130,7 @@ DIRS=\
 	net\
 	net/dict\
 	net/textproto\
-	netchan\
+	old/netchan\
 	old/regexp\
 	old/template\
 	os\

src/pkg/netchan/Makefile → src/pkg/old/netchan/Makefile

@@ -2,12 +2,12 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-include ../../Make.inc
+include ../../../Make.inc
 
-TARG=netchan
+TARG=old/netchan
 GOFILES=\
 	common.go\
 	export.go\
 	import.go\
 
-include ../../Make.pkg
+include ../../../Make.pkg