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/GetUserInfo.php

@@ -0,0 +1,37 @@
+<?php
+
+// ### Obtain Access Token From Refresh Token
+require __DIR__ . '/../bootstrap.php';
+
+use PayPal\Auth\OpenId\PPOpenIdTokenInfo;
+use PayPal\Auth\OpenId\PPOpenIdUserInfo;
+
+// To obtain User Info, you have to follow three steps in general.
+// First, you need to obtain user's consent to retrieve the information you want.
+// This is explained in the example "ObtainUserConsent.php".
+
+// Once you get the user's consent, the end result would be long lived refresh token.
+// This refresh token should be stored in a permanent storage for later use.
+
+// Lastly, when you need to retrieve the user information, you need to generate the short lived access token
+// to retreive the information. The short lived access token can be retrieved using the example shown in
+// "GenerateAccessTokenFromRefreshToken.php", or as shown below
+
+// You can retrieve the refresh token by executing ObtainUserConsent.php and store the refresh token
+$refreshToken = 'yzX4AkmMyBKR4on7vB5he-tDu38s24Zy-kTibhSuqA8kTdy0Yinxj7NpAyULx0bxqC5G8dbXOt0aVMlMmtpiVmSzhcjVZhYDM7WUQLC9KpaXGBHyltJPkLLQkXE';
+
+try {
+
+    $tokenInfo = new PPOpenIdTokeninfo();
+    $tokenInfo = $tokenInfo->createFromRefreshToken(array('refresh_token' => $refreshToken), $apiContext);
+
+    $params = array('access_token' => $tokenInfo->getAccessToken());
+    $userInfo = PPOpenIdUserinfo::getUserinfo($params, $apiContext);
+
+} catch (PayPal\Exception\PPConnectionException $ex) {
+    echo "Exception: " . $ex->getMessage() . PHP_EOL;
+    var_dump($ex->getData());
+    exit(1);
+}
+
+print_result("User Information", "User Info", $userInfo->getUserId(), $userInfo->toJSON(JSON_PRETTY_PRINT));