Shopify/active_merchant — pull request #858 by melari (2013-09-24 20:15:22+00:00)
Title: Add PayuPaisa gateway

This adds the PayU.in Paisa offsite gateway, which is based of the standard PayU.in gateway. I make use of inheritance for the most part as there are only a few subtle changes to do with the `item_id` being sent as `udf2`, and the checksum algorithm.

This is tested and working with Shopify

@odorcicd @RichardBlair
/cc @louiskearns