Woocommerce Returns and Warranty Requests 2.5.6

* Fix - Warning notice on stripslashes.
* Tweak - Updates to the warranty request form.

* Fix - Deprecated notice in upcoming WooCommerce 3.1.
* Fix - PHP notices on non array variable.
* Fix - Defined variable causing wrong behavior when moving order to processing.

* Fix - Update for WooCommerce 3.0 compatibility.
* Fix - Fatal error on product title when searching for a user to create a new warranty request.
* Fix - Page selection on Warranties > Manage Warranties for Products per Page
* Fix - Issue with warranty label not appearing on variable products.
* Tweak: Update all deprecated WooCommerce API calls
* Bug fix: Fixed email variables not getting loaded into the proper tables
* Bug fix: Fixed tooltip display loading