fixes #317

To easily add new mvc controllers (e.g. from extensions) a new
annotation `@AdminController` is added.

Streamline the Hazelcast support with boot 1.3 and support storing events in hazelcast

closes #113

 * Use @EventListener instead of ApplicationListener-interface
 * Don't inherit ClientApplicationEvent from ApplicationEvent - so JournaledEvent isn't needed anymore
 * added eclipse formatter rules
 * reformatted all files

Added a simple event journal, jorunaling all ClientApplicationEvents using a simple, non-persistent store. So all information is lost after restart. Added corresponding view to UI.