Constant TAR_PATH_PREFIX_V0 

const TAR_PATH_PREFIX_V0: &str = "./";

In v0 format, we use this relative path prefix. I think I chose this by looking at the current Fedora base image tar stream. However, several others don’t do this and have paths be relative by simply omitting ./, i.e. the tar stream contains usr/bin/bash and not ./usr/bin/bash. The former looks cleaner to me, so in v1 we drop it.