This fixes strange displays in some cases, including whereis showing
many duplicate locations, and showing more total copies than actually
exist.
It's unknown if that lead to data loss when eg, dropping. At the moment,
it seems unlikely it could, since the UUID with \r's appended is not the
same as a UUID without, and so no remote matches it.
It's also unknown if \r's can leak in on windows, perhaps when merging the
git-annex branch.
