ci: git update-index --chmod=+x upload_nuget.sh

ci: +nuget uploading script, with better error reporting

ci: curl should fall back to --fail if --fail-with-body doesn't work

ci: update nuget readme, add utility

ci: Allow pass even if docker upload fails; set docker image to imaze…

…n/imageflow_tool

ci: fix docker push tags, labels

ci: .nuspec now needs <licenseUrl>https://aka.ms/deprecateLicenseUrl<…

…/licenseUrl>

ci: fix test_zip.ps1, make compression level adjustable

build.rs scripts now parallelize with rayon (not sure of tradeoff)

nuget: fix, add icon, add s3 uploads