Impacted versions:
10.0
Steps to reproduce:
1. Create Customer Invoice and Validate
2. Make Payments on Payments screen and confirm
3. Open Manual Payments and Invocies and try to reconcile hitting CTRL-Enter for mass reconciliation

Current behavior:
Odoo server error raised with traceback
File "/home/odoo/runbot/extra/runbot/static/build/188623-10-0-347494/odoo/addons/account/models/account_move.py", line 729, in process_reconciliations
    self.process_reconciliation(datum['mv_line_ids'], datum['new_mv_line_dicts'])
TypeError: process_reconciliation() takes exactly 2 arguments (3 given)

Expected behavior:

Video/Screenshot link (optional):
![image](https://cloud.githubusercontent.com/assets/17149532/21532189/3596954a-cd4e-11e6-94fa-be2195bd9f7b.png)


addons/account/models/account_move.py
#if 
        if writeoff_acc_id and writeoff_journal_id and remaining_moves:
            all_aml_share_same_currency = all([x.currency_id == self[0].currency_id for x in self])
            writeoff_vals = {
                'account_id': writeoff_acc_id.id,
                'journal_id': writeoff_journal_id.id
            }
            if not all_aml_share_same_currency:
                writeoff_vals['amount_currency'] = False
            writeoff_to_reconcile = remaining_moves._create_writeoff(writeoff_vals)
            #add 
            remaining_moves = (remaining_moves + writeoff_to_reconcile).auto_reconcile_lines()
            return writeoff_to_reconcile
        return True
    def _create_writeoff(self, vals):
        """ Create a writeoff move for the account.move.lines in self. If debit/credit is not specified in vals,
            the writeoff amount will be computed as the sum of amount_residual of the given recordset.
            :param vals: dict containing values suitable fot account_move_line.create(). The data in vals will
                be processed to create bot writeoff acount.move.line and their enclosing account.move.
        """
        # Ch
        if 'account_id' not in vals or 'journal_id' not in vals:
            raise UserError(_("It is mandatory to specify an account and a journal to create a write-off."))
        if ('debit' in vals) ^ ('credit' in vals):
            raise UserError(_("Either pass both debit and credit or none."))
        if 'date' not in vals:
            vals['date'] = self._context.get('date_p') or time.strftime('%Y-%m-%d')
        if 'name' not in vals:
            vals['name'] = self._context.get('comment') or _('Write-Off')
        if 'analytic_account_id' not in vals: