Also adjust Rose's mass

Estimated mass was being scaled linearly, not cubically.

The 'show ratios' option now shows how many of the second entity
fit into the first entity if it has a capacity attribute

I want to redo them and put them in Objects. I'll do
that soon

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.

Also make 'earth' a valid unit

This usually happens when the window gets unfocused before
the screenshot is done. The promise is now handled properly.
Unhandled promise errors will now cause a popup. The popup
can only appear once now.