[REF] stock_account, product: moved the standard price historization in...

[REF] stock_account, product: moved the standard price historization in 'product' module, as it doesn't depend of stock (or account) at all and it was causing problems for products created before stock_account was installed, like all demo data products (no entry for them in prices_history table)

bzr revid: qdp-launchpad@openerp.com-20131206103150-2mnvsipy9uai3xlk