Port of the existing module stock_orderpoint_creator for 7.0.

Modified:
- view to be valid in 7.0,
- removed the redefinition of the field product_id, since the product's UOM is verified by a constraint now in procurement; it's still there but mandatory.

PR moved from Launchpad: https://code.launchpad.net/~camptocamp/stock-logistic-warehouse/7.0-port-stock-orderpoint-creator-mdh/+merge/220466