Actual delta updates for Thrive

[hhyyrylainen]

One of the main points of having a launcher (besides automatic updates) was to make the updates smaller.

This is probably quite difficult to set up as I haven't found any existing format we could adapt for this purpose so we need a packing script that makes delta updates between 7z files generated for each release.

[hhyyrylainen]

Maybe a tool like https://github.com/itchio/wharf would work. I haven't found any good other generic delta update libraries. Bundling rsync with the launcher and using that could also work but isn't really optimal.

[hhyyrylainen]

Launcher releases are so small by themselves that when auto-updating the launcher delta updates aren't really necessary.