Calculate & update the tiles correctly
No need to extract year from construction_year

construction_year used to be datetime, but is now integer.
Increase default eve pagination size
Add geojson of tz regions
First steps towards a more dynamic dashboard

* use dc.js to coordinate between charts
* only works on regional level due to data transfer sizes
* currently hardcoded to a single region
* plot sizes and gridster layout also static

Next steps are to integrate this with the rest of the page.
First steps towards a dynamic dashboard based on dc.

These changes should have been part of commit
a50309487253ebd6493ac8a1a883507d6527f52c
Region is no longer hardcoded.

- Dropdown to select the region (should eventually be replaced by a map)
- Some cleanups & refactoring, more needed