Add events system

[luttje]

A system where users are encouraged to earn more points. Events will track X amount of points during period Y through Z. Upon completion the event closes with a certain message. Headmasters will manually follow up on the event by unlocking another event. With this set-up headmasters can react to IRL actions of users and customize the next events.

Texts for the events are manually added in views, this way it is possible to uniquely style each event. The view will also display event completion messages.