Huggingface downloader / cache, offline mode

[bmilde]

It would be nice to have an option for the downloader so that it isn't pulling git from huggingface if the model is already downloaded on the disk and cached. Right now, even if the model is cached a query to huggingface is made. Also if there is no internet or no connection to huggingface, there seems to be no timeout and the downloder hangs.

[kamo-naoyuki]

I'll implement it (if i have time)