Impacted versions:

[9.0]
Tested in runbot http://174550-9-0-10dcec.runbot10.odoo.com/

Steps to reproduce:

Set the Tax Calculation Rounding Method to "Round Globally" 
Create a Sales Order with the following lines with 7% taxes

1) 5,095.20 
2) 523.20 
3) 80.64 
4) 54.12 
5) 182.00 
6) 186.20 
![image](https://cloud.githubusercontent.com/assets/16055718/19144073/309aa082-8bda-11e6-81d0-2461c4e9a467.png)

Create a Sales Invoice with the same lines with 7% taxes
![image](https://cloud.githubusercontent.com/assets/16055718/19144078/38048b58-8bda-11e6-9c2b-4b501cfa1e12.png)

Current behavior:

The total taxes in Sales Order are $477.48 

The total taxes in Sales Invoice are $477.50 

Expected behavior:

Both the total taxes in Sales Order and Sales Invoice should be 477.50 

Video/Screenshot link (optional):

addons/sale/sale.py
return
        addr = self.partner_id.address_get(['delivery', 'invoice'])
        values = {
            'pricelist_id': self.partner_id.property_product_pricelist and self.partner_id.property_product_pricelist.id or False,
            'payment_term_id': self.partner_id.property_payment_term_id and self.partner_id.property_payment_term_id.id or False,
            'partner_invoice_id': addr['invoice'],
            'partner_shipping_id': addr['delivery'],
        }
        if self.env.user.company_id.sale_note:
            values['note'] = self.with_context(lang=self.partner_id.lang).env.user.company_id.sale_note
        if self.partner_id.user_id:
            values['user_id'] = self.partner_id.user_id.id
        if self.partner_id.team_id:
            values['team_id'] = self.partner_id.team_id.id
        self.update(values)
    @api.model
    def create(self, vals):
        if vals.get('name', 'New') == 'New':
            vals['name'] = self.env['ir.sequence'].next_by_code('sale.order') or 'New'
        
        if any(f not in vals for f in ['partner_invoice_id', 'partner_shipping_id', 'pricelist_id']):
            partner = self.env['res.partner'].browse(vals.get('partner_id'))
            addr = partner.address_get(['delivery', 'invoice'])
            vals['partner_invoice_id'] = vals.setdefault('partner_invoice_id', addr['invoice'])
            vals['partner_shipping_id'] = vals.setdefault('partner_shipping_id', addr['delivery'])
            vals['pricelist_id'] = vals.setdefault('pricelist_id', partner.property_product_pricelist and partner.property_product_pricelist.id)
        result = super(SaleOrder, self).create(vals)
        return result
    @api.multi
    def _prepare_invoice(self):