Dynamic pages and a lot of structural fixes

Add event table that contains rules and description, removes some assumptions about events, and stores the data in the db instead.

Mainpage and rules are now loaded from the database, and are configurable from the admin page, which is now much more competent.

Also changes so that $event is not the string "nxNR" but the event object.

This begins the work on moving away from the heavy nitroxy dependency.