Report de Carrito - Reportes de Carrito para WooCommerce 1.5.2

* Fix an issue where non carts could be deleted

* Fix array access error

* QIT fixes and upadtes

* Fix a bug where carts could fail to be saved.

HPOS compatibility

* Fix an issue where high traffic situations could cause non carts to be deleted.

* Additional translation strings

* Only show subtotal when available