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

if not round_tax:
            prec += 5
        base_values = self.env.context.get('base_values')
        if not base_values:
            total_excluded = total_included = base = round(price_unit * quantity, prec)
        else:
            total_excluded, total_included, base = base_values
        
        
        
        
        for tax in self.sorted(key=lambda r: r.sequence):
            if tax.amount_type == 'group':
                children = tax.children_tax_ids.with_context(base_values=(total_excluded, total_included, base))
                ret = children.compute_all(price_unit, currency, quantity, product, partner)
                total_excluded = ret['total_excluded']
                base = ret['base'] if tax.include_base_amount else base
                total_included = ret['total_included']
                tax_amount = total_included - total_excluded
                taxes += ret['taxes']
                continue
            tax_amount = tax._compute_amount(base, price_unit, quantity, product, partner)
            if not round_tax:
                tax_amount = round(tax_amount, prec)
            else:
                tax_amount = currency.round(tax_amount)
            if tax.price_include:
                total_excluded -= tax_amount
                base -= tax_amount
            else: