Improvements on Account Voucher Payment

Module affected:
account_voucher_payment.

When you make or receive a bank payment some banking information is needed:
-If is a Check:
Origin Bank.
Check Number.
Destination Bank (Not Bank Journal)
-If is a wire tranfer:
Origin Bank.
Wire tranfer number.
Destination Bank (Not bank Journal).
-If is Banking Aknowledge:
Aknowledge number.
Destination Bank (Not bank Journal).
Improvement 1:
The Comun Characteristic is NUMBER of transacton, i think in all countries the money trough banks is managed with this reference, to avoid doubly entry by mistake we must have a field on lines with unique SQL contraint restriction, and this field must have by name "Transacton Number".
This Field must be shown whn you will make a bank reconciliation.
 With this improvement we'll achieve 2 things:
-- A Simple way to control the payments and receive of money "not in the Accounting point of view" but "Operatonal point of view".
-- A way to make the banking reconciliation more efficient.

Show only
If is receive voucher, only payments with balance <> 0.
if is payment voucher exactly like befor line.