Organized the files better, and added info comments.
Triangulation is working.
Editors now zoom on the mouse cursor, and added version number.
Made the area editor have a background image, and completed all associated GUI stuff.
Vertices/linedefs can now be merged.
Triangulation with inner polygons now works fine.
I THINK it's actually working now.
Area editor is pretty much entirely working, bar object editing.
More fixes on triangulation. ...I'll stop assuming that it's working fine this time, because every time I do, it's still broken.
Area editor is pretty much done, except for selecting special objects (ship, nectar, etc.) when editing mobs.
Area editor done.