http.download: fix for new changes
http.download: ?download-to -> download-to-once Hopefully better name for a word that caches the download instead of downloading every time.
factor: update download to return path and using lists fix dead url for unixdict.txt
http.download: move download words to their own vocabulary
io.files: implement (file-writer-secure) We want a way to open a temp file securely and return the stream. Opening a file to reserve the filename is not enough in some cases according to https://tldp.org/HOWTO/Secure-Programs-HOWTO/avoid-race.html