/**
 * Change Log
 *
 * v0.1.1
 *   + Hived Paypal payment method from the old v0.1.4 'checkout'
 *     module into the new payment plugin framework.
 *   + Changed interaction with PayPal cart so that each
 *     item/product combi is a separate order line in the cart,
 *     and quantities are shown properly in the cart also.
 *
 * v0.1.2
 *   + Updated for later APIs
 *
 * v0.1.3
 *   + Added persistent storage for Paypal details that used
 *     to be in the CheckoutTransaction.
 *   + Updated to work with Checkout v0.1.7
 *
 * v0.1.4
 *   + Updated for modified storage of transaction amount as string
 *     by checkout module.
 *   + Captured buyer's notes from PayPal transaction (if provided)
 *
 * v0.1.5
 *   + Updated for Beta 4 templating
 *   + Added translation support
 *   + Improved installation and initial configuration
 *   + Added 'payment cancelled' page and sent URL to paypal in button
 *
 * v0.1.6
 *   + Changed module to use new event listeners in Checkout v0.1.9 to
 *     empty cart on order completion, and to notify when IPN receives
 *     notification of completed payment in correct amount (to allow
 *     fulfilment to commence)
 *
 * v0.1.7
 *   + Updated to automatically set return, cancel, and IPN URLs.  It is
 *     no longer necessary to manually configure these in the PayPal
 *     account, hence multi-site installs will now work properly.
 *
 * v0.1.8
 *   + Updated to support per-item pricing as implemented in Checkout v0.1.11
 *
 * v0.1.9
 *   + Updated for Gallery 2.1 APIs
 *
 */