Samples for All Invoice Operations including QR Code

- Invoice search method is static now
- Shipping Info has proper Phone Params
- Small Changes to Image Class
- Updated Sample Docs

sample/invoice/RecordRefund.php

@@ -0,0 +1,38 @@
+<?php
+
+// # Record Refund Sample
+// This sample code demonstrate how you can record
+// an invoice as refunded.
+
+/** @var Invoice $invoice */
+$invoice = require 'RecordPayment.php';
+
+use PayPal\Api\Invoice;
+use PayPal\Api\RefundDetail;
+
+try {
+    // ### Record Object
+    // Create a RefundDetail object, and fill in the required fields
+    // You can use the new way of injecting json directly to the object.
+    $refund = new RefundDetail(
+        '{
+          "date" : "2014-07-06 03:30:00 PST",
+          "note" : "Refund provided by cash."
+        }'
+    );
+
+    // ### Record Refund for Invoice
+    // Record a refund on invoice object by calling the
+    // `recordRefund` method
+    // on the Invoice class by passing a valid
+    // notification object
+    // (See bootstrap.php for more on `ApiContext`)
+    $refundStatus = $invoice->recordRefund($refund, $apiContext);
+} catch (Exception $ex) {
+    ResultPrinter::printError("Refund for Invoice", "Invoice", null, $refundStatus, $ex);
+    exit(1);
+}
+
+ResultPrinter::printResult("Refund for Invoice", "Invoice", $invoice->getId(), $refund, null);
+
+return $invoice;