Support ajax add to cart

[helgatheviking]

could possibly add a parameter to toggle ajax? typically an add to cart button needs to have add_to_cart_button and ajax_add_to_cart and the data-product_id attribute for it to automatically have the WooCommerce ajax add to scripts kick in.

Unsure how quantity inputs would be handled (possibly add data-quantity to the button. and finally, may not work well with custom product types.