Fix fiscal position templates

Fix fiscal position templates
Fix tax templates
Add a tax template "TVA 0% import (achat)"
Set sequence to 10 on all tax templates, to make it easier to manually defined taxes that must have a lower sequence (eco-taxes for example)
Update the "Code" field on tax templates to a meaning-full value
End the double definition of the tax templates (was defined in both fr_tax.xml and fr_pcg_taxes.xml ; now only in fr_tax.xml)
Fix typo in tax codes
Remove "classes 8" accounts, which are not official legal accounts
Update module description

lp bug: https://launchpad.net/bugs/924234 fixed

bzr revid: alexis@via.ecp.fr-20120423230316-ecx6lk6sc2mr2y2z