[MERGE] l10n_es: Complete refactoring of l10n_es, courtesy of @pedrobaeza

See also:
- https://code.launchpad.net/~pedro.baeza/openobject-addons/7.0-l10n_es-refactorized/+merge/196809
- http://serviciosbaeza.com/blog/43-refactorizacion-de-l10n-es-para-openerp-v7
Merge branch 'master' of https://github.com/odoo/odoo