Updated the finance scenario for odoo 8.0

Changes:

 * res.currency.rate.type have been removed
 * some fields on products are no longer there (procure and supply
   methods)

I propose this PR on master at least to keep a trace, I don't know if we want
to merge the 8.0 scenario, breaking the 7 one, or not. I believe that the
scenarii will be extracted so this branch could be a basis for the extraction.