Dec 19, 2019

- Improve the map style:
* Show contour lines, and some other objects with more details in low zoom levels.
* Show vegetation regions with clearer colors.
* More colorful names.
* Icon size will increase when zoom in.
- Fix a track logger issue related to waypoint modification.
- Fix some crash issues in some old devices, after migrated to the new map engine.
- Fix some other issues.
- Add attributions to some 3rd party libraries.