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

third_party/psutil/psutil/_psutil_linux.h

Index: third_party/psutil/psutil/_psutil_linux.h
diff --git a/third_party/psutil/psutil/_psutil_linux.h b/third_party/psutil/psutil/_psutil_linux.h
index 1dc36c80b08e662b2f62c1763ba7bf04c8cd698c..c5e3f14ff179a25786ec75abf02a3af88648af2f 100644
--- a/third_party/psutil/psutil/_psutil_linux.h
+++ b/third_party/psutil/psutil/_psutil_linux.h
@@ -1,5 +1,5 @@
 /*
- * $Id: _psutil_linux.h 1142 2011-10-05 18:45:49Z g.rodola $
+ * $Id: _psutil_linux.h 1166 2011-10-17 22:18:07Z 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
@@ -13,4 +13,5 @@
 static PyObject* linux_ioprio_get(PyObject* self, PyObject* args);
 static PyObject* linux_ioprio_set(PyObject* self, PyObject* args);
 static PyObject* get_disk_partitions(PyObject* self, PyObject* args);
+static PyObject* get_physmem(PyObject* self, PyObject* args);