[X] make relation between user and events
[X] make scoreboard for events
[X] make access mod for events :
    [X] Sub button for public events
    [X] Access by password
    [X] Begin date for display challenges
    [X] Ending date for stop flag submission

[X] Admin rights
    [X] Admin can access to events pages without password
    [X] Admin can subscribe to event without password

[X] process flag submission
    [X] increment user score in Scores model

[X] add filters for admin dashboard
[X] add search in fields in admin dashboard
[X] display more information in admin dashboard

Front End :
[X] Smooth display of events listing
[X] Nice page with background, logo etc for event detail