We need someone to code is a PHP class to allow us to easily interface into the Chase Paymentech/Orbital payment gateway. It should use the Online XML API. The full documentation of the XML can be found here: http://tinyurl.com/pweng2. The code must follow best practices for PHP security. The code must produce and submit well formed XML, and be able to receive and process XML responses properly. The code must be able to pass certification testing by Chase. The class needs to have...