Custom User Registration Fields for WooCommerce 2.2.4

* Fix - Fixed a security vulnerability that could allow unauthenticated privilege escalation during checkout.
* Fix - Additional validation added to user role assignment on registration and My Account page.

* Fix - Add QIT test.

* Update - Updated compatibility for latest WordPress and WooCommerce versions.

v2.1.3
* Update - Tested & updated compatibility with latest WooCommerce versions.

v2.1.2
* Fix - Fixed bug with file uploads.
* Fix - Fixed error due to unseralize.

Fix - Fixed fields not showing on my account page.

* Fixed Security Vulnerabilities.

* Fixed typos.