Inkscape now exits before it finishes writing its files, somehow.
So, we need to wait for the files to be created. The Blender
add-on also now correctly configures the lineart to use the
secondary camera, which is rotated to avoid errors when rendering
orthographically.

Also update the add-on to allow for configuration of
potrace's alpha settings, which controls how strongly
it favors straight lines. This makes things like buildings
look a lot nicer.

Also update the Blender scripts to use red/green/blue areas
instead of light and dark ones. This also allows for
three colors now.

That was a Blender thing. Also updates the process-model
script so that it runs some stuff in parallel, which might
make it slightly less agonizingly slow.

(just a credit card for now, though). This also introduces some fixes
to the process-model script, allowing for it to compensate for the
extra height introduced by the line art. blender-model.py is adjusted
to allow for this, and makeModel() now checks for the bottom/extra
values produced by the process.

Also add some tweaks to the process-model script that I managed to lose.

Also adjust Rose's mass

This also updates the model-processing script to automatically
insert the model data into the appropriate source file.

I also significantly rewrote the process-potrace-model-forms.py
script, as well as the blender-model.py script. Most of the other
scripts are old; I removed some personal info from them, so they
don't work properly now.