Add onSale flag to ProductList (view) and ProductVariantList (view)
Merge pull request #907 from rustyswayne/1.4.1

Started work on the subscriptions API provider
Merge branch 'feature/extended-product-views' of https://github.com/opmaat/Merchello into opmaat-feature/extended-product-views
Merge remote-tracking branch 'merchello/1.4.1' into 1.4.1