fixed error handling on Graph call

- applied pull request #57 and #69 from the facebook-php-sdk
- Fixed errorhandling in private method "makeRequest", to be consistend
with the errorhandling in the facebook-php-sdk: throwing a
"FacebookApiException" containing error code, message and type
- updated shared assembly "Newtonsoft.Json" to v4.0.30319. Source code
remains compatible with previous versious.
advised use for mixing assembly versions is to use a bindingRedirect
entry in web.config
- updated example accordingly
- cleaned up non-sourcecode files