Finished and tested AIMesh

- Fixed AIMesh and is now tested and working! Could be slightly off due
to coordinate conversions, but fek it. It works pretty much. I haven't
run into issues.
- getY now returns -̶1̶3̶3̶7̶ -99999 when AImesh is not loaded or when
there's nothing there.
- Added support for larger AIMesh textures.
- writeFile now puts the X in red, Y in green, and the height value in
blue. Note that Our Y goes from down to up ingame, but it's the other
way around in the heighttexture.
- Credited my teacher for the line function
- Added UpwardDisplacement to objects