improvement: added new filter wp_all_import_recount_terms_after_import
improvement: Allow add variations as linked products
bug fix: compatibility with woo commerce 2.6
bug fix: error on activation without WP All Import
bug fix: grouping variable products
bug fix: Set parent product outofstock if all variations are outofstock
bug fix: import stock status for 5th type of import variable products
bug fix: do not update stock_status if _stock is not set to update
