Payment plugins functions explained

This info is meant for developers who want to create the payment plugin for a particular payment system for DJ-Classifieds.

Important functions:

1. onPaymentMethodList - this function is used for displaying particular payment method on DJ-Classifieds payments methods list (after filling the 'Add the advert' form)
2. process - diplays the form that is being sent to payment gateway website. This form is hidden and contains all payment data. Javascript code submits form so user sees only text on frontend: "Please wait - redirecting to Paypal (for example).
3. _notify_url - this function receives data from payment gateway website, parses it and activates the advert