Please note that the script is not at all production-ready,
but it's juuust so enough for our purposes.
I have no idea how other people generate reproducible tars. I tried:
- 'tar' simply doesn't honor --exclude-cvs-ignore on my machine.
- 'tar' with --exclude-from=.gitignore requires including
`git config --global core.excludesfile`, which requires
tilde-expansion, which I simply don't grasp.
- `git archive` doesn't include submodules.
