* Tweak - Don't return zero when the customer funds balance is negative.
* Tweak - Tested compatibility with WP 5.8. * Fix - The funds were not being added to the customer account when using the top-up form
* Feature - Sell deposit products at a sale price. * Feature - Support recurring deposit products with the extension "All products for WooCommerce Subscriptions". * Tweak - Tested compatibility up to WC 5.5. * Dev - Added class autoloader.
