Paid Memberships Pro - Pay by Check 0.12.1

* ENHANCEMENT: Tweaked the confirmation message on the confirmation page to clearly show that no access is available until payment is received.
* ENHANCEMENT: Improved cases where orders would stay in pending if members checked out for the same level but change their payment method. Previous orders now are set with the "token" status if switching gateways and had a pending status with check payment.
* BUG FIX: Improved compatibility for cases like Auto Renewal Checkbox where a level may have recurring and non-recurring options. This fixes an issue where non-recurring members would still be cancelled or receive renewal reminders.
* BUG FIX: Various fixes to support and improve compatibility with PHP8+ (Thanks @ZebulanStanphill, @jarrydlong).
* BUG FIX: Fixed an issue where [membership level="0"] would display incorrectly (Thanks @ipokkel)

* ENHANCEMENT: Improved SQL queries around sending email reminders, cancelling outstanding memberships.
* ENHANCEMENT: Support PayFast gateway.
* ENHANCEMENT: Support PayPal Website Payments Pro.

* BUG FIX: Fixed issue when using PMPro v2.1+.
* BUG FIX: Fixed issue with billing address or payment info fields not being shown when switching back to the default gateway after having an error with checking out by check.