ProductBundle and LayeredNavigationBundle changes
ProductBundle and LayeredNavigationBundle changes

- changed default sorting to hierarchy.
- added variant options to product datasets
- added indexes on SKU columns
- added attribute filtering option
- added unique to SKU
- fixed variant editor to keep attribute group selected for product

WellCommerce/AppBundle,diversantvlz/WellCommerce,WellCommerce/OAuthBundle,WellCommerce/CoreBundle,WellCommerce/WellCommerce,WellCommerce/AppBundle,WellCommerce/CatalogBundle,WellCommerce/SearchBundle,WellCommerce/CatalogBundle,WellCommerce/wellcommerce-default-theme,WellCommerce/WellCommerce,WellCommerce/CouponBundle,diversantvlz/WellCommerce,WellCommerce/RoutingBundle,WellCommerce/OrderBundle,WellCommerce/WellCommerce,WellCommerce/CmsBundle,WellCommerce/ReviewBundle,diversantvlz/WellCommerce,WellCommerce/OrderBundle,WellCommerce/WishlistBundle,WellCommerce/CouponBundle,WellCommerce/ReviewBundle,WellCommerce/CmsBundle,WellCommerce/CoreBundle,WellCommerce/wellcommerce-default-theme,WellCommerce/AppBundle