Add boot-services milestone marker for boot; fixed udev-addon init time.

system-services.conf

Index: system-services.conf
diff --git a/system-services.conf b/system-services.conf
index 576d00bdf317baefabb7a7b83a9759df606ed395..2e11187f65286d60d6fe482cfc27593242a35bcb 100644
--- a/system-services.conf
+++ b/system-services.conf
@@ -1,4 +1,4 @@
-# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -12,13 +12,16 @@ author          "chromium-os-dev@chromium.org"
 # session, but that should start once at boot time, possibly staying
 # up for the life of the system.
 #
+# NOTE: jobs depending on this job can assume that boot-services
+# have been started.
+#
 # Standard usage:
 #   start on starting system-services
 #   stop on stopping system-services
 # Jobs that normally terminate in a bounded time (i.e. don't use
 # 'respawn') should omit the 'stop on' stanza.
 
-start on stopped boot-complete
+start on stopped boot-complete and started boot-services
 stop on starting halt or starting reboot
 
 # We only want to start once, but 'stopped boot-complete' happens