title: Woocommerce: Which hook to replace deprecated "woocommerce_add_order_item_meta"
body: <p>Need to add custom meta to order items. Googled it and most articles says to use "woocommerce_add_order_item_meta" hook. This hook is deprecated in the newest version 2.3.7. Someone, please tell me which hook to use instead.</p>
  
  <p><a href="http://docs.woothemes.com/wc-apidocs/function-woocommerce_add_order_item_meta.html" rel="noreferrer">http://docs.woothemes.com/wc-apidocs/function-woocommerce_add_order_item_meta.html</a> </p>