We're version 3 now (and a quick 3.1 update!)
I had little time to test it, but it should work okay.

3.1 Filenames and authors again

• "conditional_dnp" is no longer an artist.
• If you encounter any more trash author tags, let me know.
• All invalid filenames should now be ignored.

3.0 Filenames and authors

• Moved off from "md5 only"
• Tool will remove all dots and underlines from all filenames in directory. Not able to remove other invalid sybols yet.
• Tool will now calculate md5 if file is not named after the checksum and try to use it for search.
• Added PULLER.bat and md5.exe to implement that. Still not a virus.
• Will now save author to the "creator" (author in windows) field as well as into tags!
• Keeping it in tags just in case someone's software only works with one field, not with both tags and authors. For now.
• Will save author to xmp-dc:creator
• Only 1 artist per picture at the moment.
• Removed excessive -api PNGEarlyXMP when calling exiftool. We don't need that for JPG files. We still do need that for PNGs, for some reason.