YITH WooCommerce Color and Label Variations Premium 2.8.1

* New: Support to WooCommerce 3.7.0 RC1
* New: Support to WordPress 5.2.2
* New: New plugin admin panel style
* Update: Plugin Core

* Tweak: get value of default language term if translated value is missing
* Update: plugin fw 3.2.1
* Fix: check on $sitepress variable
* Fix: js error missing variation on loop
* Fix: removed WP main query setup from gallery code
* Dev: new js trigger 'yith_wccl_reset_loop_form'

* New: Support to WooCommerce 3.6.0 RC1
* New: Support to WordPress 5.1
* New: Support to Eola theme (by Mikado Themes)
* Update: Plugin Core
* Update: Spanish translation
* Fix: Get parent variations gallery for WPML translated products.
* Dev: New filter "yith_wccl_use_parent_gallery_for_translated_products"