@gvaish #2 More refactoring for response and typed responses

* ErrorInfo: Error information.
* Facebook: getMe returns Future<SONObject>, updated API calls.
* IResponseHandler, Request, Response: Deleted.
* ModelBase: Base model. All models inherit from this.
* Me: Stub for the model representing response of "/me"
* FacebookTest: Let the methods throw an exception, don't catch
* sample-local.properties: Sample file for local.properties.