trigger an error if a nonliteral context is pushed to the server (through a new object_hook) bzr revid: xmo@openerp.com-20121126140525-ni2x5m56upss610b
bzr revid: xmo@openerp.com-20121126105450-0f6xowd3dhj4jmbl
bzr revid: al@openerp.com-20121010203753-azrcz3k2kd44ni24