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, modify the Blender add-on so that mass can be
computed via density even if a volume is not being included

Also update the add-on a bit to fix some errors

Also update the scripts to support tagging entities
with masses and volumes.

Also updates the add-on some more. It can now
assign materials based on face maps, which the
Building Tools add-on creates automatically

Also put the export part back into the main
Illustrator script

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

Also update the Illustrator scripts

Also adds an Illustrator script that automatically
handles all of the tracing