WooCommerce Product Add-Ons 6.8.2

* Fix - Currencies with comma separator not saving.
* Fix - Revert per line item level add-ons.

* Fix - Admin settings display sometimes not refreshed to new 3.0 version. Add versioning to CSS.
* Fix - Non required radio buttons causes undefined error when selecting on None.
* Fix - Remove file upload path from displaying on line item summary.
* Fix - When show tax inclusive on shop/pages is enabled, summary amount not reflecting tax.
* Fix - When saving price type settings, the type gets reverted to previous settings in certain cases.

* New - Flat fee based pricing.
* New - Percentage based pricing.
* New - Image swatches.
* New - Display add-ons as line items.
* Fix - Plugin prefix has been added to meta data so its identifyable.
* Fix - Cannot edit product if default label is empty.
* Add - Error handling on filesize limits.