[FIX] add correct toString for KeyNotFound and ObjectNotFound
[FIX] add correct toString for KeyNotFound and ObjectNotFound

--HG--
extra : convert_revision : xmo%40openerp.com-20110331122018-1p122l55tdf325lq

splbio/openerp-web,gisce/openerp-web,vnc-biz/openerp-web,splbio/openerp-web,vnc-biz/openerp-web,vnc-biz/openerp-web,MarkusTeufelberger/openerp-web,MarkusTeufelberger/openerp-web,gisce/openerp-web,splbio/openerp-web,vnc-biz/openerp-web,gisce/openerp-web,MarkusTeufelberger/openerp-web