Google Analytics for Payment API

Adds Google Analytics tracking for ecommerce transactions processed using the Payment API module.

As the Payment API can be used with a wide variety of forms, this module isn't able to add the full range of necessary data fields to the page by itself. It depends on the modules implementing the individual Pay Forms to fill in fields such as the customer's address and products purchased. Two hooks are provided for this purpose: hook_pay_googleanalytics_transaction_alter() and hook_pay_googleanalytics_products_alter().