* New - sort products by SKU
* New - filter by 'Allow Backorders'
* New - support to WooCommerce 3.7
* Update - plugin framework
* Update - language files
* Fix - label for 'Stock quantity' field in Filters
* Fix - bulk edit tabs freeze on hover
* Tweak - prevent issue when product is not set
* Tweak - fixed issue when selecting products on filters
* Dev - added yith_wcbep_allow_editing_custom_fields_in_variations filter
* Dev - added yith_wcbep_save_custom_field_{} filter