WooCommerce Chained Products 3.7.0

* Fix: WooCommerce Bookings emails not being send when Chained Products is active

* Fix: Search for variable products returning parent variable product
* Fix: Mini Cart count count sets to zero when 'sa_cp_show_chained_items' filter was used
* Fix: Compatibility notices and warnings when 'sa_show_chained_item_price' is set to yes

* New: WooCommerce 3.0 compatible
* New: WooCommerce Subscriptions 2.2.0 compatible
* Fix: UI issue on order screen for WooCommerce less than 3.0
* Fix: When hide out of stock items in checked then the parent product should hide too if chained product is out of stock.
* Fix: Take backorders into consideration for chained products
* Update: Class structure for frontend code
* Update: Will now support only WooCommmerce 2.5+