Some fixes if stock not applied on context
Some fixes if stock not applied on context

TheVirtualLtd/bda.plone.cart,andreesg/bda.plone.cart,andreesg/bda.plone.cart,TheVirtualLtd/bda.plone.cart,TheVirtualLtd/bda.plone.cart,andreesg/bda.plone.cart,andreesg/bda.plone.cart,TheVirtualLtd/bda.plone.cart