Add logout success handler with a service parameter

[tdb85]

Our typical convention for our web applications is to have CAS logouts include a URL back to the application so they don't get stuck at the CAS logout screen.

This is particularly useful when you want to log out from one user and back in as another.

I've added a service which accepts route & parameters as additional parameters. This could perhaps be added to the existing LogoutSuccessHandler class, but I liked the idea of keeping that as a clean simple class when there are simple requirements.

[drupol]

Hi,

I don't know if this package is still maintained and no offense will be taken by the maintainer of it, but the service parameter in logout handler is handled in this package: https://github.com/ecphp/cas-bundle

If this message is an issue, feel free to delete it as well.