[IMP] account_payment: add invoice / transaction link

Purpose of this commit is to add a link between invoices and transactions
to store payment data like what is already done for sale orders.

 * add payment_tx_id on account.invoice model that stores the last
   transaction; also add the acquirer related on the tx;
 * add a stat button on invoice with links to all transactions linked
   to that invoice;
 * add account_invoice_id on payment.transaction model that stores the
   link to the invoice;
 * add the inverse one2many from invoice to all its transactions so
   that we can browse them if necessary;

0 files changed, 0 insertions, 0 deletions