- Do not have a default product for displayable variants
- Include the ability to change the product_group and gang_member in the product form
 - Add validation so shiipping and tax categories are mandontory
- Add preperation work for cache digests
- Add link so we can navigate to the displayable variants from the product page
- Added caching logic for taxon index page
Merge branch 'watg' of github.com:watg/spree into watg