Change for all tiered shipping modules: If no tiers match (for lowest tier), do not return a rate.
Clear existing ship rates before fetching new ones.
Add the .shoppage CSS class
Fixed #2955 Call add_to_cart() not addtocart()
Fixed #2953 Corrected the product property check for downloads
Merge branch 'issue/2953' into 1.3.x
Merge branch 'issue/2955' into 1.3.x
Fix typo in fb81faf57d0a0f37c952ecaebac5b15154270237
Merge branch 'TieredShippingFix' into 1.3.x
#2953 Fixed flipped logic
Merge branch 'issue/2953' into 1.3.x
Disable submit button in checkout to prevent duplicate order submission

Added SHOPP_SUBMIT_TIMEOUT macro