[6.1/7.0] module : account_easy_reconcile - should never modify manual reconcile

[Frederic Clementi - Camptocamp]

Automatic reconcile delete and replace some partial reconcile done by user manually

To reproduce:
- Create a customer invoice for 10000 € to Customer X (customer account: 4110000) - Add a reference : ABC1234 and validate the invoice to book it into ledger
- Pay partialy that invoice (8000€) using the bank statement...but fill in a different reference (XYZ789) - Confirm the bank statement - the payment entry will be posted.
- Reconcile manually the invoice and the partial payment
- Create a new bank statement to record a 2nd partial payment for that invoice (1500€) but this time the reference is the same than the one use on the invoice entry (ABC1234) .
- Lauch the automatic reconcile on the receivable account

The bug is the following:
- The system will create a partial reconcile between the invoice and 2nd payment without including the 1st payment done manualy reconciled (because this one do not have the same reference).
- the initial partial reconcile is broken because linked to only 1 account move line (the other one being now reconciled with the 2nd payment)

[Frederic Clementi - Camptocamp (frederic-clementi)]

As possible correction : I suggest that all partial reconciles (full reconcile are already ignored) with the type 'manual' should never be modified by the automatic reconcile.