should probably go through a testing phase (checking its result
against that of eval_domain_and_context) for a while, but apart from
that it's supposed to work.
'stdlib' stuff (datetime.date.today, datetime.timedelta,
time.localtime, time.time, time.strftime) still need to be
written. Isn't there also a dateutil.relativedeleta somewhere?
Anyway that needs to be done and the various evaluation contexts need
to be defined, but the valuator itself should mostly work.
bzr revid: xmo@openerp.com-20120227073721-nkgeiqacbzch8xev