Add l10n_ch_hr_payroll.

Swizerland Payroll Rules for Odoo.

Features list :
* Add Swiss salary rule categories
* Add Swiss salary rules
* Add children in school to employee
* Add LPP range to contract
You can add a `'summary'` in `__openerp__.py` to say in a short sentence what does this module. It will be displayed in module list and on apps.odoo.com