Check in work in progress to move to another machine.
Checkpoint, since I think I've found a good way to do it.

Right floats still don't work, though.
Refactor ExclusionShapeInfo to remove copying.
Fix use of coordinates!
Fix style complaints
Refactor and optimize segment generation.
More updates for style.
Add a test.
Initial changelogs.
Add vertical writing mode tests.
Changes for patch upload + first iteration
make the bots happy
first part of review feedback