Support url to download zip from HTTP(s) server using Range header

[agix]

Zip format doesn't allow real unzipping from a stream as it starts from the end and you can't really know the end of a stream.

Nevertheless, it doesn't mean you absolutely need the entire zip on your disk.

As long as you know the size of the zip file, and you are able to read part of it based on offset, it can be unzipped without touching the disk.

This PR aim to provide this feature from HTTP(S) server supporting Range header:

https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests

The server should also respond the size of the file via HEAD request in Content-length response header (which is pretty standard).

[tsibley]

I'd like to see this feature!