Settings-defined projections
Principles:
- Client-side: The map should have a projection defined in the settings, and EPSG:3857 by default
- Back-end: The data should be served with a projection defined in the settings, and EPSG:4326 by default
How-to:
- Replace EPSG:31370 by settings-defined projections.
- Data must be reprojected by OpenLayers
Some inspiration from cartofixer
Other requirement (maybe another issue): Init map with X, Y, Zoom values defined in settings.