Updates to LIPP & Future Payments

- Updated LIPP Sample code
- Updated Future Payments to have helper functions for retrieving access token
- Updated Logging Syntax to include timestamp and response json

sample/lipp/UserConsentRedirect.php

@@ -0,0 +1,28 @@
+<?php
+
+require __DIR__ . '/../bootstrap.php';
+
+use PayPal\Auth\Openid\PPOpenIdTokeninfo;
+use PayPal\Exception\PPConnectionException;
+
+session_start();
+
+// ### User Consent Response
+// PayPal would redirect the user to the redirect_uri mentioned when creating the consent URL.
+// The user would then able to retrieve the access token by getting the code, which is returned as a GET parameter.
+if (isset($_GET['success']) && $_GET['success'] == 'true') {
+
+    $code = $_GET['code'];
+
+    try {
+        // Obtain Authorization Code from Code, Client ID and Client Secret
+        $accessToken = PPOpenIdTokeninfo::createFromAuthorizationCode(array('code' => $code), null, null, $apiContext);
+    } catch (PPConnectionException $ex) {
+            echo "Exception: " . $ex->getMessage() . PHP_EOL;
+            var_dump($ex->getData());
+            exit(1);
+    }
+
+    print_result("Obtained Access Token", "Access Token", $accessToken->getAccessToken(), $accessToken);
+
+}