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

failsafe-delay.conf

Index: failsafe-delay.conf
diff --git a/failsafe-delay.conf b/failsafe-delay.conf
index b15f95d0ed8e5e3dcafb0c95088a05ff8fcdcd60..3f92096a7f588006e51694202975d0475a7ba433 100644
--- a/failsafe-delay.conf
+++ b/failsafe-delay.conf
@@ -8,7 +8,11 @@ author          "chromium-os-dev@chromium.org"
 # This job is used as the guarantee that the "failsafe" job will start.
 # It's a separate job to allow failsafe to start on normal conditions
 # before the timer here expires.
+#
+# NOTE: We purposely don't start the delay until boot-services
+# have finished starting up so that people waiting on failsafe
+# can always assume that boot-services are there.
 
-start on runlevel 2
+start on started boot-services
 
 exec sleep 30