Make rebundling faster by generating multiple bundles in parallel
Rebundling the whole 8.0a10 release on build-sunet-a.torproject.net is taking ~ 12 hours.
I think one part that is taking a lot of time is the creation of the mar/tar.xz/dmg/exe files of the bundles in all the languages, which is done sequentially, with the mar/tar/dmg/nsis tools probably using only one thread. We could probably make that part faster by generating multiple locales in parallel.