WooCommerce Points and Rewards 1.8.11

* Fix - Points log order by points not working.

* Fix - Typo $points_earnedo should be $points_earned

* Fix - My Account Points tab not found after visiting permalinks page.
* Fix - Allow usage of % sign in points modifier field for coupons.
* Fix - Round points at the last possible moment to avoid rounding errors.
* Fix - Improve compatibility with product discounts applied by WooCommerce Memberships
* Fix - PHP notice for non-numeric value on the cart screen.