WooCommerce Waitlist 2.5.0

* Ensured backwards compatibility for waitlist templates
* Fixed bug where users were not archived if in stock mail failed to send
* Added common errors to waitlist panel when mailouts failed
* Added exporter and eraser for personal data (included in WordPress 4.9.6)
* Fix: bug with mailouts sometimes causing error due to too few parameters on header/footer actions
* Updated template loading path to utilise WooCommerce defaults (templates should now be placed in the "woocommerce" theme folder)
* Added functionality to export waitlists
* Ensured frontend JS was available on any page
* Minified assets

* Fix: Minimum stock amount not working due to typo on option name

* Fix: Users not always removed from waitlists when they make a purchase for the prouct
* Fix: Mailouts are now only sent when the stock level increases
* Added filter for adjustment of time delay between when a user can receive another waitlist notification