Add button "Add to payment/debit order" on invoice form view
Started to integrate payment transfer in account_payment_order (not finished at all though)
Various fixes/changes/improvements/...
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
This port to v9 is not finished... there is still a lot of work:
- finish the code of account_payment_order/wizard/account_payment_line_create.py
- port account_banking_payment_transfer and integrate it inside account_payment_order
- fix bugs
- clean-up code, remove dead code
- test in several complex scenarios
