Rewrite of many parts and now using the new backend

- The backend archives data and we should be able to ask for previous dates.
- We can also select a custom range of dates (this is not saved between refresh).
- Stats are done server-side, so no more complex stuff here.
- We can have more display styles. Light theme to come.
- Grid now can have colors for each show, as requested by people online.
  If implemented, we could use pre-defined colors provided by the backend.
- On mobile layout (1 col.) changing the route will make you scroll to the content.
- In dev environement Raven and Google Analytics are not used.