WooCommerce Pre-Orders 2.1.0

* Update - WC tested up to version.

* Fix - Issue where Shop Loop Product Message setting is not applied to product taxonomy page.
* Fix - Stock is not reducing when a Pre Order is charge upon release and using Pay Later option.
* Fix - Charge upon release date not shown on Thank You page.
* Fix - Email site name token not correctly replaced.
* Update - Email templates to include $email object as variable.

* Fix - Issue where updating non pre-order orders' status may throws an error.
* Fix - Missing space between custom message and status transition message.
* Fix - Issue where pre-order orders may not be processed when there's pre-order product without availability date/time.