Whitespace!
Fix basket form issue for group products

The change in 72c3d7cf broke validation for group products as it tested
if the user could add the initial product to his/her basket.  This fails
for group products as they have no stock.
Relocate the 'edit this product' link

Made smaller and moved to avoid shifting the basic page layout.
ProductClass admin now includes inline for ProductAttribute
Housekeeping