[New] Added New l10n_it_base refactored and new l10n_it_pec

Hi!
as discuss on https://github.com/OCA/l10n-italy/issues/2 I made this pull request.

The l10n_it_base now is a simple configuration module.
I created a l10n_it_pec that add a field for mail on the partner profile after the normal mail

Regards

Franco
This Hack is in the odoo main code,like here:

https://github.com/odoo/odoo/blob/master/addons/account/res_config.py#L205

I insert that in the main code, because future improvement of that module is to set defaults behavior of future module in the l10n_it localization like ir.defaults configs or direct fields in the res.company object and so on.