impr: a simple shell

[XWasHere]

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this pr adds a small shell that can upload, download and delete files + list and create directories

it also makes a minor change of setting the mime type of directories to application/x-directory

[XWasHere]

ok so i'm sure i look like a massive idiot, but i forgot that i had suggested the mime types for folders change a while ago but it got rejected, and seeing as this change depends on that, i'm going to close this pr.

[XWasHere]

i believe that this should work most of the time without changing the content type, i added a parse_dir function to check if the response is a directory listing. it won't work if it receives a file that looks identical to a directory but i doubt that would be a problem under normal circumstances.

[5HT2]

I'll take a look at this when I have time, thanks