Add missing Product class.

Task #072807

__init__.py

@@ -8,6 +8,7 @@ from . import stock
 def register():
     Pool.register(
         stock.Template,
+        stock.Product,
         stock.Move,
         stock.SplitMoveStart,
         module='stock_serial_number', type_='model')

stock.py

@@ -26,6 +26,10 @@ class Template(metaclass=PoolMeta):
         'product in quantities diferent than 1.')
 
 
+class Product(metaclass=PoolMeta):
+    __name__ = 'product.product'
+
+
 class Move(metaclass=PoolMeta):
     __name__ = 'stock.move'