Impacted versions:
master

Steps to reproduce:
On the video

Current behavior:
You have to write the name of the group only

Expected behavior:
Either Writing the code or the name of an Account Group fetch the record 

Video/Screenshot link (optional):
https://drive.google.com/file/d/0B1w9gokcJL9hVWpaMTdGQ3RlLTQ/view

addons/account/models/account.py
new_prefix = self._get_sequence_prefix(vals['code'], refund=False)
                journal.sequence_id.write({'prefix': new_prefix})
                if journal.refund_sequence_id:
                    new_prefix = self._get_sequence_prefix(vals['code'], refund=True)
                    journal.refund_sequence_id.write({'prefix': new_prefix})
            if 'currency_id' in vals:
                if not 'default_debit_account_id' in vals and self.default_debit_account_id:
                    self.default_debit_account_id.currency_id = vals['currency_id']
                if not 'default_credit_account_id' in vals and self.default_credit_account_id:
                    self.default_credit_account_id.currency_id = vals['currency_id']
            if 'bank_account_id' in vals and not vals.get('bank_account_id'):
                raise UserError(_('You cannot empty the bank account once set.'))
        result = super(AccountJournal, self).write(vals)
        
        if 'bank_acc_number' in vals:
            for journal in self.filtered(lambda r: r.type == 'bank' and not r.bank_account_id):
                journal.set_bank_account(vals.get('bank_acc_number'), vals.get('bank_id'))
        
        if vals.get('refund_sequence'):
            for journal in self.filtered(lambda j: j.type in ('sale', 'purchase') and not j.refund_sequence_id):
                journal_vals = {
                    'name': journal.name,
                    'company_id': journal.company_id.id,
                    'code': journal.code,
                    'refund_sequence_number_next': vals.get('refund_sequence_number_next', journal.refund_sequence_number_next),
                }
                journal.refund_sequence_id = self.sudo()._create_sequence(journal_vals, refund=True).id
        return result
    @api.model
    def _get_sequence_prefix(self, code, refund=False):