Change the Product module reference to TestopiaProduct

Source: http://mozilla.6506.n7.nabble.com/Need-help-on-Product-methods-in-testopia-py-td203236.html

NOTE: The new module does not have the exact same functionality as the old one!
        * some of the product-related methods in this script don't work as intended because of this

Signed-off-by: Stoicescu Corneliu <corneliux.stoicescu@intel.com>