W3C Fix for FacebookRedirectLoginHelper.php

Change & to &amp; to be compilant with W3C checks.
Rename FacebookRequestException to FacebookResponseException
Update FacebookApp tests and add copyright header
Fix Mockery
Merge pull request #165 from yguedidi/facebook-app-tests

Update FacebookApp tests and add copyright header
Merge pull request #164 from yguedidi/facebook-response-exception

Rename FacebookRequestException to FacebookResponseException
Merge pull request #166 from yguedidi/fix-mockery

Fix Mockery
Merge pull request #156 from micressor/patch-1

W3C Fix for FacebookRedirectLoginHelper.php
Add FacebookRequest entity
Add FacebookResponse entity
Add FacebookBatchRequest entity
Add FacebookBatchResponse entity
Add FacebookClient class
Update FacebookResponseException to use FacebookResponse
Add Code entity
Update AccessToken entity and associate it with a FacebookApp entity
Add DebugAccessToken entity
Update SignedRequest entity and associate it with a FacebookApp entity
Update helpers to use FacebookClient and FacebookApp
Add request and batch request builders