[FIX] account: invoiced button values must be calculated as the user

Otherwise, if done with the superuser:
 - The multi-company rules won't work, the user will have the amount of all invoices, cross-companies
 - The amount currency will always be the currency of the superuser
[FIX] account: several fixes on the new bank statement reconciliation widget
[FIX] correct css computation to remove unnecessary toolbar
[FIX] website_sale: customer write on public user and the sale order is apply to public user if the public user is active=True; the checkout layout display state_id field twice
[FIX] im_chat : enable chat widget only for base.group_user
[ADD] doc's readme

* also only enable linkcode if Sphinx >= 1.2
* fix html inline roles?
[ADD] support for a version switcher in odoo theme thing

needs beauty input
[FIX] base: remove test_ir_model, which causes bugs

The test in test_ir_model creates a custom model.  This causes a full reload of
the registry, which recursively installs the required modules while 'base' is
being tested.  As a side effect, it commits stuff from the database, so that
the effects of test_ir_model are actually not rolled back.
[IMP] models: "X in self" is now equivalent to any(X == rec for rec in self)