OLFDB

For the turn around issue the turn_around_penalty and turn_around_penalty2 values have to be set in the vehicleprofile. Just did some tests with demo device and it works fine.

I digged further into the truck routing issue today. The routing engine is capable of doing this. The problem is that the data needed for this to work is not...

I have opened a [PR](https://github.com/navit-gps/navit/pull/1106) now, but needs changes as code factor is complaining about complexity.

For a working build see [my fork](https://github.com/OLFDB/navit/tree/macosbuild). CI passes for all OS builds. There are still some issues with the graphics. I have used gtk_drawing_area with the internal GUI. The...

Do I need to change anything for this PR to get merged?

After converting some maps using maptool: how to handle e.g. below_default for the height? If we convert this height to 0 the way gets not flagged, but it will definitely...

Added conditional speed limits. WIP. As for truck routing conditional speed limits are quite common, I added them to maptool and routing. It's still WIP for the parser of conditions,...

Added vertical meters to the heightline widget in internal gui as that might be of interest planning a route with a truck, or bike, or pedestrian. 

Improvements for conditional speed limits. Backward limits are supported as well. Improved gui, now showing icons for danger, hazmat and wet condition. Hazmat conditions shown only if vehicle has hazmat...

Finally the routing taking into account the low emissions zones is working. I think the PR is finished now. https://user-images.githubusercontent.com/5459286/119258878-e46c7380-bbcb-11eb-9ffb-0385843c21c0.mov