Apparently STOP codes (a.k.a. color changes) should be by themselves, not
attached to another stitch. To add a STOP code at a given stitch, we should
clone the stitch and then set the STOP command on the new stitch.
You can't have a module and a package named the same thing. PyInstaller wants
to import the main script as if it were a module, and this doesn't work unless
there's no directory of the same name with a __init__.py in it.