Done:
1)added unsubscribe
2)reworked tables: added associated table to store users who subscribed for events
Need to:
1) add jstl & some cosmetics for web UI (actually, web-UI should be fully reworked)
2) add deleteEvent
3) add logout
4) rework links on pages (to logout or go to index from everywhere for ex.) and make available only one action link for user (such as subscribe/delete/unsubscribe)