When moving images, Spritely does not always clean up after itself

[adam-coster]

On at least one occasion a few subimages were copied but their source not removed, and that resulted in the following error:

Error: EBUSY: resource busy or locked, rmdir '..\SpritelyExports\tile_grass'
    at Object.rmdirSync (fs.js:881:3)
    at Object.fixSprites (...\node_modules@bscotch\spritely\build\cli\util.js:126:32)
    at async runCliCommand (...\node_modules@bscotch\spritely\build\cli\spritely-bleed.js:11:5)

This could be due to the operating system preventing deletion of the files because they were open somewhere else -- I've been unable to replicate.

More frequently some folders get left behind, even when none are being obviously used by other applications. So for unable to intentionally replicate.