Release 7.3

Change with release 7.3

- Remove compatibility code for BVR/ESR only Multi BVR/ESR is supported
- Add credit control integration with ESR
- Add intergation with account bank reconciliation addons https://launchpad.net/banking-addons/bank-statement-reconcile-7.0 with module l10n_ch_payment_slip_base_transaction_id
- Uniformize management of reference