Develop demo application for web service authentication

[alranel]

In order to show how to use CIE for TLS/SSL client authentication, it would be nice to provide developers with source code of a demo application that performs a connection to a secure web service, which would in turn log or display the contents of the client certificate.

Example code for this task can be found in https://github.com/italia/cie-middleware/tree/master/EsempioCSP

(Note for people participating in Hack.Developers: this is the root certificate used for signing the authentication certificate of the test CIE cards available during the event: TestCA.cer.zip It should be added to the trust list of the target server.)