Impacted versions: Master - probably all

Steps to reproduce:
Go to Settings Screen

Current behavior:
You'll see Authentification written twice.  In English, and especially in English technology speak the usual word is Authentication.

The only real issue it causes is that when searching for docs, you would search for Authentication (e.g. "How do I setup Oauth Authentication with provider x?"

Expected behavior:

Video/Screenshot link (optional):
![image](https://user-images.githubusercontent.com/5093264/29589757-99092af0-87ea-11e7-8bbe-dd8593b54d42.png)

Seems it occurs 4 times in code, but didn't want to PR as I don't understand translations
![image](https://user-images.githubusercontent.com/5093264/29589851-1e30f71c-87eb-11e7-94a7-fdb16a9eeccf.png)

FIx if you want, close if you want, I won't be offended and can manage


addons/base_setup/models/res_config_settings.py
module_inter_company_rules = fields.Boolean("Manage Inter Company")
    module_pad = fields.Boolean("Collaborative Pads")
    module_voip = fields.Boolean("Asterisk (VoIP)")
    company_share_partner = fields.Boolean(string='Share partners to all companies',
        help="Share your partners to all companies defined in your instance.\n"
             " * Checked : Partners are visible for every companies, even if a company is defined on the partner.\n"
             " * Unchecked : Each company can see only its partner (partners where company is defined). Partners not related to a company are visible for all companies.")
    default_custom_report_footer = fields.Boolean("Custom Report Footer")
    report_footer = fields.Text(related="company_id.report_footer", string='Custom Report Footer', help="Footer text displayed at the bottom of all reports.")
    group_multi_currency = fields.Boolean(string='Multi-Currencies',
            implied_group='base.group_multi_currency',
            help="Allows to work in a multi currency environment")
    paperformat_id = fields.Many2one(related="company_id.paperformat_id", string='Paper format')
    external_report_layout = fields.Selection(related="company_id.external_report_layout")
    @api.model
    def get_values(self):
        res = super(ResConfigSettings, self).get_values()
        params = self.env['ir.config_parameter'].sudo()
        default_external_email_server = params.get_param('base_setup.default_external_email_server', default=False)
        default_user_rights = params.get_param('base_setup.default_user_rights', default=False)
        default_custom_report_footer = params.get_param('base_setup.default_custom_report_footer', default=False)
        res.update(
            default_external_email_server=default_external_email_server,
            default_user_rights=default_user_rights,
            default_custom_report_footer=default_custom_report_footer,
            company_share_partner=not self.env.ref('base.res_partner_rule').active,
        )
        return res
    @api.multi
    def set_values(self):