Case: User can't add invoices to payment/debit orders from the tree view but it's still possible to add them one by one from the form view.
- Remove binding_views="form": by default are "tree & form".
With this fix, users can add payment/debit orders from the invoice tree view
* Removed deprecated YAML tests.
* Removed document dependency, as now there's no attachment dropdown.
* Switched deprecated `compute` method of res.currency.
* Restored missing field `reference_type` in invoices.
* Fixed call to `message_post`.
* Added missing description in model.
Improvements include:
- full re-organisation of modules and big re-organisation of the code
- simplification of the code related to the fact that support for direct debit is now in t
he base module, not added by an optional module account_direct_debit (module was removed)
- new design of the wizard to select move lines to pay
- support for non-SEPA file transfer-
- support for German direct debit SEPA files (fixes bug #129)
- remove workflow of payment.order
- add wizard of selection of move lines to pay
