res.users: invalidate cache when a user is modified. [Bug 664379]
res.users: invalidate cache when a user is modified. [Bug 664379]

Original description, by Xavier ALT:
> The server is using a variable name "_uid_cache" for authentication
> caching, but this variable is never clear when user informations change,
> that means if we disable a user or change it's password their requests
> are still allowed (cached auth check ok).
>
> This affects OpenERP v5 (server/bin/service/security.py) and OpenERP v6
> (server/bin/addons/base/res/res_users.py, class users).
>
> The only workaround is to restart the server.
>

xrg/openerp-server,xrg/openerp-server