Add support for downloading to cloud

[fernacolo]

You mention "a supercomputer is required". How about adding scripts that creates compute and disk resources at Azure and/or AWS, and download data there?

[surak]

I am not sure how useful it is, since runs of the codes which use such datasets can get pretty expensive on cloud premises when we talk about dozens of thousands of nodes with low-latency interconnects (does AWS have infiniband?). But you are more than welcome to submit a patch and we can add it! Thanks a lot!