[feature] compressed downloads

[colinbrislawn]

Scenario:

Cart could be optionally compressed to accelerate download speed of compressible data. This could be added as a button on the file naming step.

Supporting both tar.gz and .zip would be helpful for Windows users, as Windows machines can not natively open .tar.gz files, while .zip is fully cross platform.

[dmlb2000]

Adding zip as a possible extension format does have it's issues. https://docs.python.org/2/library/zipfile.html The limits for zip are pretty lame, 2Gb for single file and 4Gb for total size. Zip64 does have reasonable limits, though if we default to zip64 then some users would have issues extracting a zip64. Even on Windows platforms that's an additional client download.

So my thoughts are to put the heuristic to detect the limits on zip then simply produce an error if you request bad sizes. The default should be maintained as tar and zip64 would be an alternative for folks to specify.