[IMP] note: res_user new api migration (WIP)
[FIX] note: stage_id inverse method no longer api.one to avoid error when creating a note from the form view
[IMP] note: res_user converted to models.Model instead of osv.Model
[IMP] note: remove unnecessary method decorator
[IMP] note: import dateformat from openerp.tools instead of redefining it inline
[IMP] note: res_user override uses new api