most changes about stages. Override in project_mrp is back therefore. bzr revid: tde@openerp.com-20131023113716-jw8jh1jvn4dgpcyr
bzr revid: stw-c7b064849fe1f51bf264dd2de76920ded909d158
bzr revid: pinky-dedd7f8a42bd4557112a0513082691b8590ad6cc