Update Leaflet and change map tile server.

Update leaflet to 0.7.3 and change tile source from cloudmade to 
opencyclemap.
Update to Django 1.7
Add CupPoints model and a second event mode.
Small enhancements and bugfixes.
Fix statistics.

Also, don't show progress per day on one-day events.
Improve Participation handling.
Make use of URL namespacing.
Small change to impersonate notice.