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
""" Create new move lines from new_mv_line_dicts (if not empty) then call reconcile_partial on self and new move lines
            :param new_mv_line_dicts: list of dicts containing values suitable fot account_move_line.create()
        """
        if len(self) < 1 or len(self) + len(new_mv_line_dicts) < 2:
            raise UserError(_('A reconciliation must involve at least 2 move lines.'))
        # Cr
        if len(new_mv_line_dicts) > 0:
            writeoff_lines = self.env['account.move.line']
            company_currency = self[0].account_id.company_id.currency_id
            writeoff_currency = self[0].currency_id or company_currency
            for mv_line_dict in new_mv_line_dicts:
                if writeoff_currency != company_currency:
                    mv_line_dict['debit'] = writeoff_currency.compute(mv_line_dict['debit'], company_currency)
                    mv_line_dict['credit'] = writeoff_currency.compute(mv_line_dict['credit'], company_currency)
                writeoff_lines += self._create_writeoff(mv_line_dict)