Add psutil build step to fix pyauto media issues. Upgrade psutil to 0.4.0.

third_party/psutil/psutil/arch/bsd/process_info.c

Index: third_party/psutil/psutil/arch/bsd/process_info.c
diff --git a/third_party/psutil/psutil/arch/bsd/process_info.c b/third_party/psutil/psutil/arch/bsd/process_info.c
index d3006461db7226da8f19425529d3919dcfe9ba3b..0b2f4ab7e9311a3d5732c74511ce8bdc4ec7e8ca 100644
--- a/third_party/psutil/psutil/arch/bsd/process_info.c
+++ b/third_party/psutil/psutil/arch/bsd/process_info.c
@@ -1,5 +1,5 @@
 /*
- * $Id: process_info.c 1142 2011-10-05 18:45:49Z g.rodola $
+ * $Id: process_info.c 1187 2011-10-22 15:56:59Z g.rodola $
  *
  * Copyright (c) 2009, Jay Loden, Giampaolo Rodola'. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
@@ -20,6 +20,7 @@
 #include <sys/param.h>
 #include <sys/user.h>
 #include <sys/proc.h>
+#include <signal.h>
 
 #include "process_info.h"