VER-3

refactor to handle stateless authentication
extract event bus converter into core module
add Java serialization converter
In fact it has the same meaning for me. if you look at the `pac4jHelper.sendResponse` method, you will see that it handles additional action sent by the pac4j manager. The only difference between, say, the j2e module, is that no exception are thrown at this portion of the code between the pac4j helper and the pac4j manager are decoupled.