WooCommerce批量编辑器 2.6.9

* Fix - Minor fix in the mulicurrency filter (hook)

* New - Added the option to edit WPML mulicurrency fields (custom fields tab)
* Fix - Minor CSS fix (tabs) and other small fixes

* Fix - Minor fix when saving cogs and value is null

* Fix - Minor fixes for attributes filter (JS code)

* New - Added the option to use WooCommerce Cost of Goods field (set up in settings / integration )
* Fix - Some CSS fix for the filter menu to better fit smaller screens
* Dev - Minor fixes and improvements

* Fix - Minor JS fix for custom field (calculations) in home tab
* Fix - Removed parent product variable and only list variations

* Fix - Updated the queries and cache for improved performance and less memory usage.

Dev - Minor fix in action hooks

* Fix - Minor fix in saving attributes that contains space
* Dev - Moved sort icons to left of labels / names
* Dev - Other minor fixes and improvements

* Fix - Minor fix in setting featured image in Categories and images tab (JS)
* Fix - Minor fix in filter for categories
* Dev - Minor other fixes and improvements