Renaming Namespaces and Organizing Classes

- Updated OpenId classes to be in API namespace
- Updated PP Naming Convention to PayPal Naming Convention
- FormatConverter Class got its own namespace
- Handlers are grouped in Handler namespace
- Samples and Tests Updated Accordingly

sample/lipp/GenerateAccessTokenFromRefreshToken.php

@@ -3,14 +3,14 @@
 // ### Obtain Access Token From Refresh Token
 
 require __DIR__ . '/../bootstrap.php';
-use PayPal\Auth\Openid\PPOpenIdTokeninfo;
+use PayPal\Api\OpenIdTokeninfo;
 
 // You can retrieve the refresh token by executing ObtainUserConsent.php and store the refresh token
 $refreshToken = 'yzX4AkmMyBKR4on7vB5he-tDu38s24Zy-kTibhSuqA8kTdy0Yinxj7NpAyULx0bxqC5G8dbXOt0aVMlMmtpiVmSzhcjVZhYDM7WUQLC9KpaXGBHyltJPkLLQkXE';
 
 try {
 
-    $tokenInfo = new PPOpenIdTokeninfo();
+    $tokenInfo = new OpenIdTokeninfo();
     $tokenInfo = $tokenInfo->createFromRefreshToken(array('refresh_token' => $refreshToken), $apiContext);
 
 } catch (Exception $ex) {