TODO - Map quality

Geometry

bad polyline shifting remains
- from the remaining cases, looks like we need to totally remove some tight points and retry
- make polygons use the corrections too?
- bad polyline shifting causes jagged lane endings in generalized_trim_back
handle small roads again somehow?
- o40 has a long cut when merged, why not hit in the middle?
  - what if we allow intersections between infinite lines for merged cases?
- what's going on with O253 generally?
  - need a way to see the original untrimmed roads... want to draw them at the end, in a plugin
  - experiment with resolution
- try it bigger
- deal with loop roads?
- manually draw a picture of the weird intersection to see what would look reasonable. i think we need original road bands from deleted stuff to make decent polygons.
- model U-turns
degenerate-2's should only have one crosswalk
- then make them thinner
ped paths through sidewalk corners are totally broken
- calculate the better paths first, then make the corner geometry from that?
car turns often clip sidewalk corners now
figure out what to do about yellow center lines
- intersections on one-ways look weird
- yellow and white lines intersect cars and turn icons and such
- who should own drawing them?

if building front path intersects another building, then scrap that building.
- or wait, just require bldgs to be even closer to sidewalk first.
- need to do polygon vs polygon check!
- will need to speed it up with quadtree containing entire buildings. make sure these are easy to use.
can we make OSM buildings with holes?
- experiment with https://docs.rs/clipping/0.1.1/clipping/gh/struct.CPolygon.html and https://github.com/21re/rust-geo-booleanop